Switchgrass Response to Harvest Frequency and Time and ...nue.okstate.edu/Papers/Wade_2004.pdfSwitchgrass Response to Harvest Frequency and Time and Rate of Applied Nitrogen #

JOURNAL OF PLANT NUTRITION

Vol 27 No 7 pp 1199ndash1226 2004

Switchgrass Response to Harvest Frequency

and Time and Rate of Applied Nitrogen

W E Thomason1 W R Raun2 G V Johnson2

C M Taliaferro2 K W Freeman2 K J Wynn2

and R W Mullen2

1Samuel Roberts Noble Foundation

Ardmore Oklahoma USA2Department of Plant and Soil Science Oklahoma

State University Stillwater Oklahoma USA

ABSTRACT

Switchgrass (Panicum virgatum L) is currently being evaluated as

a raw material for producing fuel chemicals and electricity

Switchgrass biomass is bound by the growing environment that

includes fertility More information is needed on sustainable switch-

grass production as influenced by nitrogen fertility and harvest

management Field experiments were initiated at Chickasha and

Perkins OK in 1996 and 1998 respectively to evaluate switchgrass

Contribution from the Oklahoma Agricultural Experiment Station

Correspondence W E Thomason Virginia Polytechnic Institute and State

University Department of Crop and Soil Environmental Sciences 422 Smyth

Hall Blacksburg VA 24061 USA Fax 540-231-3075 E-mail wthomaso

vtedu

1199

DOI 101081PLN-120038544 0190-4167 (Print) 1532-4087 (Online)

Copyright amp 2004 by Marcel Dekker Inc wwwdekkercom

ORDER REPRINTS

response to applied nitrogen (N) at rates of 0 112 224 448 and

896 kg ha1 In addition harvest frequency and time of N application

were evaluated Yield maximums and the greatest N potassium (K)

phosphorus (P) and sulfur (S) uptake values were achieved with

448 kgNha1 applied all in April and harvested three times In fact

harvest frequency was the most important factor affecting yields

over the course of these studies with average dry matter yields of

163 147 and 129Mgha1 yr1 for three two and one harvest

yr1 respectively No significant change in soil organic carbon was

detected over time Although dry matter yields were found to decline

with time total N uptake did not Forage N concentration was found

to be greater in later years thus increasing production costs While

yields were highest (180Mgha1) with 448 kgNha1 applied all in

April and three harvests applying 0N and harvesting three times

produced almost as much total biomass (169Mgha1) This limited

response to N is possibly explained by the evolution of switchgrass

under low N conditions Increasing forage concentrations of K

magnesium (Mg) P and S were noted with increasing yields

indicating a potential for response to these nutrients

Key Words Switchgrass Panicum virgatum Nitrogen Biofuel

INTRODUCTION

Evaluation of switchgrass has shown that it is suitable for use as anenergy feedstock either for producing ethanol via bioconversiontechniques or electricity via co-firing with coal It is also beinginvestigated as a replacement for wood pulp in the paper makingprocess The energy content of switchgrass has been found to becomparable to that of wood and when the expected costs of productionare weighed against the value of the crop switchgrass was capable ofproducing five times more energy than that required to grow the crop[1]

Analysis of ash and alkali content of switchgrass has shown relatively lowalkali levels and therefore should have little slagging potential when usedin coal firing systems[1] This same research noted that due to the highcellulose content low ash levels and good fiber length to width ratiosswitchgrass could substitute for hardwood pulp in production of highquality paper Later work estimates the cost of switchgrass production ataround $30 t1 indicating that it would be viable at least on a cost basisas a replacement for wood pulp[2]

Nutrient uptake and loss from production sites are important issuesfor high-biomass producing crops such as switchgrass This is especially

1200 Thomason et al

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true if removal as in haying and not grazing is practiced Mineralcontent of switchgrass has been found to be higher on a percentage scalewith lower yields for the macronutrients N P K and calcium (Ca) Nochange in concentration for many micronutrients has been noted butconcentrations of boron (B) and manganese (Mn) have been found toincrease with increasing yields[3] Increases in plant N concentration withincreased applied N throughout the season have been noted[4] Staleyet al[5] found increasing N concentration in harvested plant parts withincreases in applied nitrogen They also found increased N uptake withincreased N rates but only in a one-harvest system Using 15N as a tracerthey attributed only 15ndash39 of total N uptake to fertilizer sources butthese uptake levels were still above those of tall fescue grown on the samemarginal sites Researchers in Pennsylvania have found N recoveries of40 of that applied and noted that this number was thought to decreaseas native soil N levels increased Measured on a daily basis switchgrasshas been found to take up 149ndash263 kgNha1 d1[6] Other researchstates that if water is not limiting then N levels account for 80 of thevariation in yields When water is limiting however the absence ofmoisture is the most important factor in yield determination[7] Depth ofsoil has been found to have little effect on N uptake[8]

Harvesting methods involving one to two cuttings each season havebeen shown to produce optimum yields in most systems[9] The earlierharvest is usually much higher in animal feed value and a two-cut systemmay allow early cuttings to be used as livestock feed and later cuttings forbiofuel production[10] Sanderson[11] found that as switchgrass maturesthrough the growing season stem components increase and leaf compo-nents decrease as a percent of total dry biomass This increase in stemportion is attributed to internode elongation necessary for plant growthand competitiveness

Switchgrass yields of 10ndash12Mgha1 have been reported inCanada[12] This led the authors to surmise that switchgrass could be avaluable source of biomass for biofuel production Hall et al[13] foundswitchgrass yields in Iowa to be near 6Mgha1 and noted a consistentresponse to added N up to 75 kgNha1

Bransby et al[14] noted switchgrass environmental benefits as an Nbuffer strip crop and as a net fixer of carbon (C) They state that the mostimportant benefit of using switchgrass as a fuel is the net cycling of C in theenvironment and give only slight importance to soil C sequestrationLong-term research in Alabama has recently shown no change in soilorganic C levels after 3 yrs in continuous switchgrass but after 10 yrs soilorganic C was 45 higher than adjacent fallow ground[15] The objectivesof this study were (1) to evaluate the response in biomass yield and uptake

Switchgrass Response to Applied Nitrogen 1201

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of N K P Ca Mg and S of switchgrass grown in Oklahoma to harvestfrequency and time and rate of applied nitrogen and (2) to evaluate theshort term effects of switchgrass production on soil organic C levels

MATERIALS AND METHODS

Two field experiments were initiated to evaluate switchgrass responseto applied N at rates of 0 112 224 448 and 896 kg ha1 In additionharvest frequency (once at the end of September twice mid-July andSeptember and three times May mid-July and September) and time ofN application (all in April 12 in April and 12 following first harvestand 13 in April 13 following first harvest and 13 following secondharvest) were evaluated (Table 1) Experiments were initiated atChickasha (Dale silt loam fine-silty mixed superactive thermic PachicHaplustoll) and Perkins (Teller sandy loam fine-loamy mixed thermicUdic Arguistoll) OK in 1996 and 1998 respectively Pre-establishmentsoil test values and soil classifications for the sites are reported in Table 2A randomized complete block design with three replications was used atboth locations with an incomplete factorial arrangement of treatments(Table 1) The northern lowland switchgrass variety lsquolsquoKanlowrsquorsquo wasbroadcast seeded in 1996 at Chickasha and 1998 at Perkins at a rate of11 kg pure live seed ha1 The stand at Chickasha was allowed a one-yearestablishment phase and harvesting began the following spring whilePerkins was planted and harvesting begun in the same year At both sitespreplant rates of 112 kgNha1 224 kg P2O5 ha

1 and 560 kgK2Oha1

were applied to the entire area Switchgrass was harvested at a heightof 10ndash15 cm using a lsquolsquoCarterrsquorsquo harvester

Forage samples were dried and ground to pass a 140-mesh sieve(100 um) and analyzed for total N content using a Carlo-Erba NA 1500automated dry combustion analyzer[16] Forage samples were alsoanalyzed for tissue concentrations of P K[17] Ca Mg and S[18]

Nutrient uptake values were calculated by multiplying the yield inkg ha1 by the elemental in the dry forage

Surface soil samples (0ndash15 cm) were taken from both experiments atinitiation and analyzed for organic carbon using dry combustion[16] Inspring 2001 bulk density samples were taken with a Giddings soil probefrom the experimental area and an adjacent area that was conventionallytilled for comparison Also in spring 2001 surface soil samples (0ndash15 cm)samples were taken between plant crowns to simulate the initial samplingand also from within the crown of the plant to evaluate samplingmethods Soil organic carbon levels (mgC cm2) were calculated as

1202 Thomason et al

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a product of bulk density (g soil cm3) core depth (cm) and soil carbonconcentration (mgCg1 soil)

Statistical evaluation and analysis of variance were performedusing SAS[19]

RESULTS

Chickasha

The Chickasha site was the only one established in time for the 1997summer harvests Central Oklahoma received timely and adequaterainfall throughout the summer and maximum production levels werein excess of 30Mgha1 (Table 3) Three harvests one early in the

Table 1 Treatment structure for switchgrass experiment Chickasha (initiated

1996) and Perkins (initiated 1998)

Trt N rate N application method of harvests

1 0 mdash One

2 0 mdash Two

3 0 mdash Three

4 112 All in April One




8 112 All in April Two




12 112 All in April Three




16 112 12 in April 12 aft 1st harvest Two




20 112 13 in April 13 aft 1st harv 13 aft 2nd harv Three





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Table

2

Initialsoilchem

icalcharacteristics

(0ndash15cm

)andclassificationatChickashaandPerkinsOK

Location

pH

a

NH

4-N

NO

3-N

Pb

Kb

TotalN

cOrganic

Cc

Dbinitial

Db2001

(mgkg1)

(mgg1)

(gcm

3)

Chickasha

69

758

112

28

215

006

82

143

141

ClassificationDale

siltloam

(fine-siltymixedsuperactive

thermic

Pachic

Haplustoll)

Perkins

67

753

21

77

325

09

68

147

147

ClassificationTellersandyloam

(fine-loamymixedactive

thermic

Udic

Argiustoll)

Dbbulk

density

(gcm

3)

apH11

soilwater

bPandKMehlich

III

cOrganic

CandtotalNdry

combustion

1204 Thomason et al

ORDER REPRINTS

summer one in late summer and one at the end of the season producedmore biomass (277Mgha1) compared to one harvest at the end of theseason (186Mgha1) These results reflect the ideal weather conditionspresent in 1997 that resulted in high yields Three harvests resulted inhigher N uptake values than those with fewer cuttings even when yieldswere higher for plots with fewer cutting dates (Table 3) The lowest Nuptake values for any treatment occurred with lower N rates (less than224 kg ha1) and one or two cuttings Three harvests increased K uptakeby the plants and split-applying the N over three dates resulted in more Kuptake than with two N application dates Neither treatment removed asmuch K as those with all N applied in April This is plausible consideringthe amount of K removed in the stems Phosphorus uptake levels wereon average approximately ten times lower than N or K uptake levelsThis was expected based on previous work documenting NP ratios of101[20] Splitting N applications over two dates resulted in lower Premoval than when applying all N early in the season (Table 3)

In 1998 a significant response to applied N was observed Howeverno differences in harvest frequency were noted probably due to the lackof rainfall in mid-summer Total yields were much lower than in 1997Lower rates of early season N and the removal of forage in late-summerdecreased yields in plots with three harvests and three-way split Napplications when compared to those cut twice Although yields werelower in 1998 maximum N uptake was higher than 1997 (375 and330 kg ha1 respectively) There was no difference in N uptake untiltotal N rates reached 224 kg ha1 Potassium uptake values were foundto follow the same trend as N Maximum K uptake occurred withthree-harvests and lowest values with one-harvest (Table 4)

Yields were again high at the Chickasha site in 1999 with some plotsproducing over 20Mgha1 (Table 5) The average yield for the site was17Mgha1 The highest levels of N uptake were observed with splitapplications of N and multiple harvests Uptake of K mirrored that forN in that number of harvests was highly significant and multipleharvests tended to remove more K than one harvest Phosphorus uptakewas greatest for three harvests regardless of N timing (353 and154 kg ha1 for three and one harvest respectively)

Yields for 2000 represent only the first two scheduled harvests for theyear and not the final end of season harvest Due to heavy fall rainsharvest was delayed and due to lack of communication the area wasburned before the final harvest could be taken Therefore yields shown inTable 6 represent the sum of only two cuttings The highest yields werecut two times (scheduled for three) and either not fertilized or fertilizedat the lowest rate of 112 kgNha1 (154 and 157Mgha1) Nitrogen


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Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable

ratesandharvestfrequencyChickashaOK1997

Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard

errorofthedifference

betweentw

oequallyreplicatedmeans

2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests

abSignificantatthe005and001probabilitylevelrespectively


ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

uptake of 240 kgNha1 was highest for two harvests (scheduled for

three) and April fertilization (Table 6) Potassium uptake was highest

with multiple harvests The lack of the final harvest for this data set

severely limited interpretation

Perkins

Yields in 1998 were lower than those at Chickasha due to sandier

soil and less total rainfall Treatment combinations with two or three

harvests and split N applications produced the highest yields averaging

over 11Mgha1 Forage nitrogen concentration did not increase

with increasing yields as was the trend over all years (Fig 1) Potassium

uptake was maximized with two harvests and either one or two N

applications both averaging near 180 kgKha1 Uptake of P was

significantly affected by N rate and was greatest with one harvest and

one N application date at 174 kg ha1 (Table 7) Phosphorus uptake

decreased with multiple harvestsPerkins again produced much lower yields than Chickasha in 1999

and significant differences were noted due to number of harvests and N

timing (Table 8) Average yields were highest for the three harvests three-

way split N treatments (Table 8) Multiple harvests increased crop N

uptake over those with the same total N rates and one harvest Potassium

uptake was high for all multiple harvest plots In fact one harvest

0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171

Figure 1 N and K concentrations with increasing dry biomass yields Chickasha

and Perkins (View this art in color at wwwdekkercom)

1214 Thomason et al

ORDER REPRINTS

removed little more than half of the K of two or three harvests (775 vs1552 kg ha1) Three harvests also resulted in increased P uptake

Dry matter yield in 2000 averaged over N rate was 133Mgha1

(Table 9) Nitrogen removal was maximized with three harvests andsplitting N into three applications (Table 9) There was a trend towardincreased N uptake with increasing harvest frequency and increasing Nrate Three harvests with N split into three increments resulted in 48more K uptake than two harvests and two N application dates (896 vs1844 kg ha1) The highest average P uptake was found for three harvestsand three-way split N applications (202 kg ha1) (Table 9)

Soil Carbon

Organic C data from in crown and between crown samples werecompared to organic C from initial samples from the area to determine ifchanges had occurred Bulk density measurements taken from theexperimental area did not differ from an adjacent area that wasconventionally tilled Initial samples indicated average soil organic C(SOC) for the site of 68 and 82mg g1 for Perkins and Chickasharespectively These results are possibly confounded by known spatialvariability in SOC reported by Raun et al[21] Contrast comparisons founda significant linear decrease in SOC with increasing N rates and twoharvests for the Chickasha crown sampling (Table 10) A significantquadratic increase was noted for Perkins in crown samples and asignificant quadratic decrease in SOC with increasing N rate was foundfor between crown samples at Chickasha Taken together there seem to beno obvious trends toward increasing or decreasing SOC at either site Thisis potentially influenced by the fact that aboveground biomass wasremoved from the site Garten and Wullschleger[22] have estimated that itmay take a decade of switchgrass production to sequester a significantmeasurable amount of soil carbon Given more time SOC may increasebut the short duration (3ndash5 yrs) of this study has provided no real evidencesupporting this increase in SOC especially in the lsquolsquobetween crownrsquorsquosamples

CONCLUSIONS

Overall forage K concentrations increased with increasing yieldwhile N concentrations were not affected (Fig 1) This suggests anincreased likelihood of obtaining a response to K rather than N in


ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable

ratesandharvestfrequencyPerkinsOK1998

Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table 10 Surface soil sample (0ndash15 cm) organic C between crowns of plants

and within crowns Chickasha and Perkins OK 2001

Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest

N rate linear ns ns ns ns

N rate quad ns ns ns ns

2 harvests

N rate linear ns a ns ns

N rate quad ns ns a ns

3 harvests


N rate quad ns a a ns

SEDmdashstandard error of the difference between two equally replicated means

2-sp N 2 harvmdash2 harvest system N applied in April and after first harvest

3-sp N 3 harvmdash3 harvest system N applied in April and after each of the first

two harvestsaSignificant at the 005 probability level

nsmdashnot significant at the 005 porbability level

1222 Thomason et al

ORDER REPRINTS

switchgrass Similarly overall P Mg and S forage concentrationsincreased with increasing yield (Fig 2)

Average dry biomass yields for one two and three harvests with 0and 448 kgNha1 applied are represented in Figs 3 and 4 for Chickashaand Perkins respectively As was expected yield levels declined with timeat Chickasha (Fig 3) However this same trend was not observed atPerkins (Fig 4) It should be noted that even with changes in dry matteryield nutrient uptake values remained constant This is a concernespecially with increased forage N as increased N uptake will increasebiomass production costs Practical production recommendations fromthis work suggest that N be applied once at the beginning of the growingseason and that N rates remain constant over the life of the stand

Since the goal of this research was to determine maximumrecommended N rates for high production switchgrass data wereaveraged over years and locations to better estimate optimum N ratesand harvest practices The highest annual yield was consistently achievedwith 448 kgNha1 applied all in April and three harvests during theseason averaging 180Mgha1 dry matter production This treatmentalso maximized N K P and S uptake However applying 0N andharvesting three times produced almost as much total biomass

y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P

Figure 2 Ca Mg P and S concentrations with increasing dry biomass yields

Chickasha and Perkins (View this art in color at wwwdekkercom)


ORDER REPRINTS

(169Mgha1) This limited response to N is possibly explained by theevolution of switchgrass under low N conditions The highest level of Cauptake was observed in plants receiving 224 kgNha1 split half in Apriland half after first harvest and harvested twice Magnesium uptake washighest where 224 kgNha1 was applied in April and with two harvestsNumber of harvests was most important in determining yields with threeharvests producing 163Mgha1 two harvests producing 147Mgha1

and one harvest averaging 129Mgha1 Multiple harvests maximized

0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1

0N 1harv0N 2harv0N 3harv448N 1harv448N 2harv448N 3harv

Figure 4 Average yearly dry matter yields over time as influenced by N rate and

harvest frequency Perkins OK 1998ndash2000 (View this art in color at

wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-



harvest frequency Chickasha OK 1997ndash2000 (View this art in color at

wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS

yields in every year when compared to one harvest While multiple

harvests have produced more forage in the early years of this study visual

observations indicate a decline in switchgrass stands after 3ndash4 years of

intensive harvest management Even though there were fewer plants in a

given area where multiple harvests were employed those treatmentsproduced more dry matter than those with higher plant density but this

may change as the stand ages If density continues to decline then at

some point biomass yield will necessarily decline It appears that

management to maximize productivity in the short-term may shorten

the life span of a switchgrass stand

REFERENCES

1 McLaughlin SB Samson R Bransby D Wiseloge A Evaluating

physical chemical and energetic properties of perennial grasses as

biofuels In Proceedings of the Seventh National Bioenergy

Conference Partnerships to Develop and Apply Biomass

Technologies Nashville TN Sept 15ndash20 19962 Fox G Girouard P Syukat Y An economic analysis of the

financial viability of switchgrass as a raw material for pulp produc-

tion in eastern Ontario Biomass and Bioenergy 1999 16 1ndash123 Balasko JA Smith D Influence of temperature and nitrogen

fertilization on the growth and composition of switchgrass and

timothy at anthesis Agron J 1971 63 853ndash8574 Madakadze JC Stewart K Peterson PR Coulman BE Smith

DL Cutting frequency and nitrogen fertilization effects on yield and

nitrogen concentration of switchgrass in a short season area Crop

Sci 1999 39 552ndash5605 Staley TE Stout WL Jung GA Nitrogen use by tall fescue and

switchgrass on acidic soils of varying water holding capacity Agron

J 1991 83 732ndash7386 Stout WL Jung GA Biomass and nitrogen accumulation in

switchgrass effects of soil and environment Agron J 1995 87

663ndash6697 Stout WL Jung GA Shaffer JA Effects of soil and nitrogen on

water use efficiency of tall fescue and switchgrass under humid

conditions Soil Sci Soc Am J 1998 52 429ndash4348 Stout WL Staley TE Shaffer JA Jung GA Quantitative

effects of soil depth and soil and fertilizer nitrogen on nitrogen

uptake by tall fescue and switchgrass Commun Soil Sci Plant Anal

1991 22 1647ndash1660


ORDER REPRINTS

9 Balasko JA Burner DM Thayne WV Yield and quality ofswitchgrass grown without soil amendments Agron J 1984 76204ndash208

10 Sanderson MA Read JC Reed RL Harvest management ofswitchgrass for biomass feedstock and forage production Agron J1999 91 5ndash10

11 Sanderson MA Morphological development of switchgrass andkleingrass Agron J 1992 84 415ndash419

12 Madakadze JC Stewart K Peterson PR Coulman BESmith DL Switchgrass biomass and chemical composition forbiofuel in eastern Canada 1999b Agron J 1999 91 696ndash701

13 Hall KE George JR Riedl RR Herbage dry matter yields ofswitchgrass big bluestem and indiangrass with N fertilizationAgron J 1982 74 47ndash51

14 Bransby DI McLaughlin SB Parrish DJ A review of carbonand nitrogen balances in switchgrass grown for energy Biomass andBioenergy 1998 14 379ndash384

15 Ma Z Wood CW Bransby DI Soil management impacts onsoil carbon sequestration by switchgrass Biomass and Bioenergy2000 18 469ndash477

16 Schepers JS Francis DD Thompson MT Simultaneousdetermination of total C total N and 15N on soil and plantmaterial Commun Soil Sci Plant Anal 1989 20 949ndash959

17 Mehlich A Mehlich number 3 extractant a modification ofMehlich number 2 extractant Commun Soil Sci Plant Anal1984 15 1409ndash1416

18 Benton JB Jr Case VW Sampling handling and analyzingplant tissue samples In Soil Testing and Plant Analysis 3rd EdWesterman RL Ed SSSA Madison WI 1990 SSSA BookSer 3 389ndash427

19 SAS Institute SASSTAT Userrsquos Guide Version 6 4th Ed SASInstitute Cary NC 1989 Vol 2

20 Cullison AE Feeds and Feeding Reston Publishing Co RestonVA 1975

21 Raun WR Solie JB Johnson GV Stone ML WhitneyRW Lees HL Sembiring H Phillips SB Micro-variability insoil test plant nutrient and yield parameters in bermudagrass SoilSci Soc Am J 1998 62 683ndash690

22 Garten GT Wullschleger SD Soil carbon dynamics beneathswitchgrass as indicated by stable isotope analysis J Environ Qual2000 29 645ndash653

1226 Thomason et al

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ORDER REPRINTS

response to applied nitrogen (N) at rates of 0 112 224 448 and

896 kg ha1 In addition harvest frequency and time of N application

were evaluated Yield maximums and the greatest N potassium (K)

phosphorus (P) and sulfur (S) uptake values were achieved with

448 kgNha1 applied all in April and harvested three times In fact

harvest frequency was the most important factor affecting yields

over the course of these studies with average dry matter yields of

163 147 and 129Mgha1 yr1 for three two and one harvest

yr1 respectively No significant change in soil organic carbon was

detected over time Although dry matter yields were found to decline

with time total N uptake did not Forage N concentration was found

to be greater in later years thus increasing production costs While

yields were highest (180Mgha1) with 448 kgNha1 applied all in

April and three harvests applying 0N and harvesting three times

produced almost as much total biomass (169Mgha1) This limited

response to N is possibly explained by the evolution of switchgrass

under low N conditions Increasing forage concentrations of K

magnesium (Mg) P and S were noted with increasing yields

indicating a potential for response to these nutrients

Key Words Switchgrass Panicum virgatum Nitrogen Biofuel

INTRODUCTION

Evaluation of switchgrass has shown that it is suitable for use as anenergy feedstock either for producing ethanol via bioconversiontechniques or electricity via co-firing with coal It is also beinginvestigated as a replacement for wood pulp in the paper makingprocess The energy content of switchgrass has been found to becomparable to that of wood and when the expected costs of productionare weighed against the value of the crop switchgrass was capable ofproducing five times more energy than that required to grow the crop[1]

Analysis of ash and alkali content of switchgrass has shown relatively lowalkali levels and therefore should have little slagging potential when usedin coal firing systems[1] This same research noted that due to the highcellulose content low ash levels and good fiber length to width ratiosswitchgrass could substitute for hardwood pulp in production of highquality paper Later work estimates the cost of switchgrass production ataround $30 t1 indicating that it would be viable at least on a cost basisas a replacement for wood pulp[2]

Nutrient uptake and loss from production sites are important issuesfor high-biomass producing crops such as switchgrass This is especially

1200 Thomason et al

ORDER REPRINTS






ORDER REPRINTS




1 and 560 kgK2Oha1





1202 Thomason et al

ORDER REPRINTS



RESULTS

Chickasha





1 0 mdash One

2 0 mdash Two

3 0 mdash Three






















ORDER REPRINTS

Table

2

Initialsoilchem

icalcharacteristics

(0ndash15cm


Location

pH

a

NH

4-N

NO

3-N

Pb

Kb

TotalN

cOrganic

Cc

Dbinitial

Db2001

(mgkg1)

(mgg1)

(gcm

3)

Chickasha

69

758

112

28

215

006

82

143

141

ClassificationDale

siltloam


thermic

Pachic

Haplustoll)

Perkins

67

753

21

77

325

09

68

147

147



thermic

Udic

Argiustoll)

Dbbulk

density

(gcm

3)

apH11

soilwater

bPandKMehlich

III

cOrganic

CandtotalNdry

combustion

1204 Thomason et al

ORDER REPRINTS






ORDER REPRINTS

Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS






ORDER REPRINTS




1 and 560 kgK2Oha1





1202 Thomason et al

ORDER REPRINTS



RESULTS

Chickasha





1 0 mdash One

2 0 mdash Two

3 0 mdash Three






















ORDER REPRINTS

Table

2

Initialsoilchem

icalcharacteristics

(0ndash15cm


Location

pH

a

NH

4-N

NO

3-N

Pb

Kb

TotalN

cOrganic

Cc

Dbinitial

Db2001

(mgkg1)

(mgg1)

(gcm

3)

Chickasha

69

758

112

28

215

006

82

143

141

ClassificationDale

siltloam


thermic

Pachic

Haplustoll)

Perkins

67

753

21

77

325

09

68

147

147



thermic

Udic

Argiustoll)

Dbbulk

density

(gcm

3)

apH11

soilwater

bPandKMehlich

III

cOrganic

CandtotalNdry

combustion

1204 Thomason et al

ORDER REPRINTS






ORDER REPRINTS

Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS




1 and 560 kgK2Oha1





1202 Thomason et al

ORDER REPRINTS



RESULTS

Chickasha





1 0 mdash One

2 0 mdash Two

3 0 mdash Three






















ORDER REPRINTS

Table

2

Initialsoilchem

icalcharacteristics

(0ndash15cm


Location

pH

a

NH

4-N

NO

3-N

Pb

Kb

TotalN

cOrganic

Cc

Dbinitial

Db2001

(mgkg1)

(mgg1)

(gcm

3)

Chickasha

69

758

112

28

215

006

82

143

141

ClassificationDale

siltloam


thermic

Pachic

Haplustoll)

Perkins

67

753

21

77

325

09

68

147

147



thermic

Udic

Argiustoll)

Dbbulk

density

(gcm

3)

apH11

soilwater

bPandKMehlich

III

cOrganic

CandtotalNdry

combustion

1204 Thomason et al

ORDER REPRINTS






ORDER REPRINTS

Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS



RESULTS

Chickasha





1 0 mdash One

2 0 mdash Two

3 0 mdash Three






















ORDER REPRINTS

Table

2

Initialsoilchem

icalcharacteristics

(0ndash15cm


Location

pH

a

NH

4-N

NO

3-N

Pb

Kb

TotalN

cOrganic

Cc

Dbinitial

Db2001

(mgkg1)

(mgg1)

(gcm

3)

Chickasha

69

758

112

28

215

006

82

143

141

ClassificationDale

siltloam


thermic

Pachic

Haplustoll)

Perkins

67

753

21

77

325

09

68

147

147



thermic

Udic

Argiustoll)

Dbbulk

density

(gcm

3)

apH11

soilwater

bPandKMehlich

III

cOrganic

CandtotalNdry

combustion

1204 Thomason et al

ORDER REPRINTS






ORDER REPRINTS

Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

2

Initialsoilchem

icalcharacteristics

(0ndash15cm


Location

pH

a

NH

4-N

NO

3-N

Pb

Kb

TotalN

cOrganic

Cc

Dbinitial

Db2001

(mgkg1)

(mgg1)

(gcm

3)

Chickasha

69

758

112

28

215

006

82

143

141

ClassificationDale

siltloam


thermic

Pachic

Haplustoll)

Perkins

67

753

21

77

325

09

68

147

147



thermic

Udic

Argiustoll)

Dbbulk

density

(gcm

3)

apH11

soilwater

bPandKMehlich

III

cOrganic

CandtotalNdry

combustion

1204 Thomason et al

ORDER REPRINTS






ORDER REPRINTS

Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS






ORDER REPRINTS

Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

3

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

238501

10941

28072

258

441

1491

191

Cutting

24132329

b709443

b1344882

b6236

b9809

11234

b4789

b

Ntiming

3361873

10535

37908

134

30

19

58

Nrate

31564708

a209208

a171088

a15333

2605

2557

534

a

CuttingaN

rate

8707859

56216

26387

393

1526

2166

302

NtimingaN

rate

6651074

41644

60091

527

1232

2031

314

Residualerror

44

478953

38207

52088

473

1924

1917

288

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

222

1650

1689

195

386

400

131

112

1harvest

174

1177

1247

134

337

372

104

224

1harvest

164

1406

1285

154

284

310

100

448

1harvest

169

1186

1311

135

322

352

105

896

1harvest

203

1541

1489

173

394

390

127

02harvests

334

2548

2612

296

552

600

208

112

2harvests

155

1536

1521

161

403

344

118

1206 Thomason et al

ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

224

2harvests

337

2825

2694

284

643

688

222

448

2harvests

296

2830

2842

310

531

589

206

896

2harvests

244

2311

2337

217

403

464

163

03harvests

267

2325

3136

267

520

594

182

112

3harvests

249

2151

2902

244

348

389

193

224

3harvests

277

2608

3358

293

420

432

237

448

3harvests

309

3000

3814

333

425

473

265

896

3harvests

286

3202

3275

268

420

449

250

112

2-spN2harv

241

2037

1976

216

420

490

160

224

2-spN2harv

253

2091

1958

219

482

492

162

448

2-spN2harv

367

3306

3413

382

626

691

243

896

2-spN2harv

202

1950

1714

212

416

424

148

112

3-spN3harv

247

2101

2677

237

354

416

220

224

3-spN3harv

199

1821

2191

202

322

342

164

448

3-spN3harv

318

2145

3687

325

490

485

251

896

3-spN3harv

291

2739

3411

313

433

469

254

SED

57

505

589

53

113

113

44

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

4

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2996539

a87600

205053

a636

9278

15536

1010

Cutting

2372035

414096

a653177

b1024

1009

1563

266

Ntiming

3576196

111018

185774

a936

4895

6344

804

Nrate

3811575

a33003

62676

a527

a4584

a5872

336

a

CuttingaN

rate

8239068

59376

64205

400

6028

10433

560

NtimingaN

rate

6168684

34597

43532

180

2624

7172

282

Residualerror

44

220581

50460

52109

412

3338

4005

318

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

166

2048

1902

221

689

592

180

112

1harvest

141

1780

1875

195

601

638

164

224

1harvest

158

2127

2119

207

698

668

183

448

1harvest

172

2170

2212

211

726

747

200

896

1harvest

100

1328

1256

117

434

430

114

02harvests

166

2232

2468

225

677

776

205

112

2harvests

112

1548

1610

169

436

438

124

224

2harvests

226

3000

3378

311

910

1046

277

1208 Thomason et al

ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

448

2harvests

147

1956

1855

187

309

300

98

896

2harvests

162

2265

2241

191

575

680

190

03harvests

215

3403

3473

280

671

819

228

112

3harvests

168

2352

2705

201

533

658

184

224

3harvests

205

2833

3432

253

616

716

205

448

3harvests

245

3756

3864

289

641

668

190

896

3harvests

147

2229

2377

189

487

537

165

112

2-spN2harv

175

2119

2455

247

614

757

213

224

2-spN2harv

200

2677

3123

289

777

846

258

448

2-spN2harv

158

2070

2464

212

601

725

200

896

2-spN2harv

156

2355

2207

220

621

609

201

112

3-spN3harv

141

1962

2110

164

425

522

140

224

3-spN3harv

146

2233

2228

183

520

567

169

448

3-spN3harv

175

2375

2739

219

531

619

172

896

3-spN3harv

135

2210

2376

172

463

534

162

SED

12

580

589

52

149

163

46

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

5

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2464423

865906

1102070

a13008

a1665

6961

a291

Cutting

245101

952918

a1038877

b14290

b139

209

2203

b

Ntiming

3120137

133208

134666

1091

3230

2274

789

a

Nrate

32430687

717517

596007

4215

1799

2500

102

CuttingaN

rate

8207490

28101

43658

250

4465

b4667

a380

NtimingaN

rate

62060595

493140

380903

3444

810

1207

159

Residualerror

44

1562737

391299

334675

3504

1491

1808

291

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

109

781

1011

124

328

380

93

112

1harvest

150

1577

1541

171

478

532

145

224

1harvest

162

1459

1954

189

436

581

131

448

1harvest

191

1800

2386

181

693

715

180

896

1harvest

114

1257

1095

104

345

363

98

02harvests

179

2278

2736

274

543

602

192

112

2harvests

132

1754

2237

211

416

432

149

224

2harvests

170

2210

2453

244

530

614

182

1210 Thomason et al

ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

448

2harvests

162

2172

2291

221

352

400

120

896

2harvests

173

2474

2514

216

534

584

180

03harvests

200

2750

3273

352

500

559

205

112

3harvests

185

3150

3450

379

533

515

249

224

3harvests

167

2787

3303

335

392

436

184

448

3harvests

191

3300

3491

368

480

530

207

896

3harvests

154

2857

3000

331

431

472

194

112

2-spN2harv

145

1794

2258

226

432

469

156

224

2-spN2harv

146

1808

2078

223

564

501

195

448

2-spN2harv

175

2181

2713

248

487

557

171

896

2-spN2harv

208

2702

3557

288

654

703

220

112

3-spN3harv

155

2220

2522

260

353

381

145

224

3-spN3harv

152

2501

2949

304

412

401

174

448

3-spN3harv

180

2707

3137

354

405

475

170

896

3-spN3harv

263

3328

3144

425

366

401

167

SED

102

1573

1494

153

100

110

38

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

6

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2194823

b35769

a23391

1497

b1151

2969

b240

a

Cutting

2325370

b727339

b1445641

b9451

b2978

b1602

769

b

Ntiming

318979

a10279

15723

60

663

380

28

Nrate

3131730

b13237

24928

765

344

1865

a124

CuttingaN

rate

874236

a32484

a29096

491

1268

a1213

105

NtimingaN

rate

629574

7762

26341

384

237

239

41

Residualerror

44

31244

8263

16602

157

352

385

52

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

mdashmdash

mdashmdash

mdashmdash

mdash

112

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

224

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

448

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

896

1harvest

mdashmdash

mdashmdash

mdashmdash

mdash

02harvests

140

1493

1923

217

320

439

132

112

2harvests

110

1252

1516

203

264

345

106

224

2harvests

125

1334

1942

193

277

418

109

1212 Thomason et al

ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

448

2harvests

117

1485

1232

185

264

361

114

896

2harvests

102

1509

1217

152

315

338

104

03harvests

154

2564

3177

317

389

481

171

112

3harvests

157

2560

3317

347

387

507

170

224

3harvests

141

2477

3183

336

376

434

177

448

3harvests

154

2719

3084

342

384

451

180

896

3harvests

92

1676

2012

170

218

258

110

112

2-spN2harv

103

1123

1262

167

225

319

97

224

2-spN2harv

125

1265

1468

192

282

404

108

448

2-spN2harv

107

1212

1350

185

232

353

98

896

2-spN2harv

106

1419

1490

164

260

325

101

112

3-spN3harv

139

2238

2762

280

346

418

154

224

3-spN3harv

120

2194

2474

268

281

361

145

448

3-spN3harv

144

2504

3053

336

338

441

178

896

3-spN3harv

112

2013

2427

259

253

297

134

SED

14

235

333

32

49

51

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS





Perkins
















0

05

1

15

2

25

3

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

KN

y = 00002x - 16581 R2= 07749

y = 5E-05x + 04825 R2= 02171



1214 Thomason et al

ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS




Soil Carbon


CONCLUSIONS



ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

7

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

273649

35478

70045

b2962

b18430

b2215

a151

Cutting

239889

137708

102599

b392

18

1398

56

Ntiming

31062

151319

7734

76

4818

105

14

Nrate

3118782

a202660

47764

157

a1925

1045

184

CuttingaN

rate

850489

92751

21729

a164

2875

1466

165

NtimingaN

rate

622391

217859

21916

189

3453

1344

161

Residualerror

44

28679

173477

12329

94

2004

620

112

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

106

1889

972

162

442

261

147

112

1harvest

84

1239

1058

136

577

268

124

224

1harvest

102

1812

1033

173

448

276

145

448

1harvest

119

1970

1530

177

535

326

166

896

1harvest

104

2349

1840

222

522

323

178

02harvests

87

1110

1283

112

330

257

110

112

2harvests

103

1596

1662

139

534

350

147

1216 Thomason et al

ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

224

2harvests

133

2082

2177

177

608

471

188

448

2harvests

110

1874

1861

133

285

232

104

896

2harvests

109

2041

2085

154

685

416

170

03harvests

121

1677

1728

170

495

393

143

112

3harvests

111

1678

1523

129

431

366

131

224

3harvests

107

1767

1711

137

461

341

140

448

3harvests

124

2038

1620

135

400

318

136

896

3harvests

104

2166

1647

144

473

312

148

112

2-spN2harv

98

1282

1455

116

423

308

127

224

2-spN2harv

118

1713

1861

141

648

386

170

448

2-spN2harv

118

1861

1995

143

537

393

167

896

2-spN2harv

119

2183

1838

145

486

346

168

112

3-spN3harv

115

1868

1662

151

514

341

136

224

3-spN3harv

109

4933

1564

135

603

329

130

448

3-spN3harv

140

2101

2266

193

647

437

161

896

3-spN3harv

90

1530

1099

91

531

295

114

SED

14

1075

287

25

116

64

27

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

8

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

230112

9728

57637

283

1049

244

24

Cutting

2111222

a130902

b262385

b1502

b2694

457

418

b

Ntiming

331828

a26761

b43367

b117

336

b204

b50

Nrate

371381

48248

b56927

b37

319

a1404

a122

CuttingaN

rate

836100

6973

15745

a105

536

178

27

NtimingaN

rate

631647

12428

8064

117

730

294

50

Residualerror

44

74364

16261

16948

134

990

432

79

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

70

379

494

85

197

123

44

112

1harvest

97

813

700

122

331

171

78

224

1harvest

72

684

614

71

232

159

60

448

1harvest

91

984

925

79

276

212

79

896

1harvest

105

1202

1142

82

316

237

92

02harvests

52

388

661

65

191

93

42

112

2harvests

88

804

1387

127

357

179

80

224

2harvests

103

1209

1819

136

321

249

98

1218 Thomason et al

ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

448

2harvests

101

1255

1809

113

227

206

73

896

2harvests

120

1603

2083

119

344

266

108

03harvests

87

1019

1133

127

307

151

79

112

3harvests

96

1133

1476

152

365

211

101

224

3harvests

101

1258

1300

152

411

208

110

448

3harvests

107

1532

1505

148

341

238

100

896

3harvests

128

2058

1747

174

329

267

127

112

2-spN2harv

69

480

907

75

233

115

49

224

2-spN2harv

88

889

1309

108

310

198

78

448

2-spN2harv

99

1045

1554

109

322

256

89

896

2-spN2harv

119

1306

1900

133

345

269

102

112

3-spN3harv

104

986

1087

149

274

174

86

224

3-spN3harv

126

1608

1547

178

398

227

114

448

3-spN3harv

109

1531

1431

126

344

230

105

896

3-spN3harv

109

1434

1441

137

304

209

100

SED

22

329

114

30

81

54

23

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

Table

9

Analysisofvariance

andmeansfortotaldry

matter

yieldN

uptake

Kuptake

Puptake

Cauptake

Mguptake

and

Suptake

forsw

itchgrass

producedunder

variable


Yield

Nuptake

Kuptake

Puptake

Cauptake

Mguptake

Suptake

Sourceofvariation

df

(meansquares)

Replication

2497183

b16971

193645

b459

a1764

a1595

a127

Cutting

2336977

a198613

b1052774

b6378

b510

8582

b789

b

Ntiming

330364

39508

a109448

a499

a697

a276

203

Nrate

392263

58709

b846

41

1104

a973

a180

a

CuttingaN

rate

825379

47535

b65231

a569

b1527

899

b233

b

NtimingaN

rate

613826

37440

b46573

327

663

629

a160

a

Residualerror

44

47696

9282

19227

140

385

385

51

TotalN

rate

(kgha1)

Cuttiming

(Mgha1)

(kgha1)

01harvest

99

436

662

39

195

70

44

112

1harvest

85

479

697

33

214

65

44

224

1harvest

117

810

1081

56

277

99

79

448

1harvest

99

835

1322

52

270

103

66

896

1harvest

126

977

1296

48

336

124

78

02harvests

91

543

921

111

233

146

61

112

2harvests

96

941

1320

118

271

188

72

224

2harvests

122

1130

1547

142

355

269

94

1220 Thomason et al

ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS

448

2harvests

112

1069

1270

126

311

239

81

896

2harvests

132

1398

1709

124

304

272

90

03harvests

137

1391

1928

232

310

234

125

112

3harvests

129

1480

1954

202

342

259

122

224

3harvests

132

1789

1982

202

347

276

133

448

3harvests

125

1948

2073

191

279

241

120

896

3harvests

143

555

518

48

130

111

38

112

2-spN2harv

95

599

973

122

252

158

62

224

2-spN2harv

106

865

867

137

367

218

82

448

2-spN2harv

112

1147

849

128

333

268

91

896

2-spN2harv

115

1186

895

125

321

264

91

112

3-spN3harv

120

1334

1681

207

295

212

109

224

3-spN3harv

128

1759

1967

211

353

251

134

448

3-spN3harv

135

2048

1875

201

342

275

148

896

3-spN3harv

131

1879

1854

188

298

253

126

SED

18

249

358

31

49

49

19

SEDmdash

standard


betweentw


2-spN2harvmdash

2harvestsystem

N

applied

inAprilandafter

firstharvest

3-spN3harvmdash

3harvestsystem

N

applied

inAprilandafter

each

ofthefirsttw

oharvests



ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS



Total N

rate

(kg ha1)

HarvestN

timing

Chickasha

(in crown)

Chickasha

(between

crown)

Perkins

(in crown)

Perkins

(between

crown)

(mgC cm1)

0 1 harvest 19138 19731 19726 16712

112 1 harvest 16655 18878 20724 17462

224 1 harvest 20967 23583 19990 15908

448 1 harvest 20714 21431 17752 16524

896 1 harvest 21457 22302 22455 17633

0 2 harvests 17607 21856 20474 13609

112 2 harvests 18285 18997 18439 16741

224 2 harvests 20262 20727 18229 14899

448 2 harvests 17877 20766 16290 13942

896 2 harvests 21788 15722 21675 17539

0 3 harvests 19018 17843 18051 14627

112 3 harvests 19823 17294 20547 16111

224 3 harvests 20844 20076 18089 14954

448 3 harvests 24617 19327 19690 15079

896 3 harvests 18579 18747 18995 15893

112 2 sp N 2 harv 15268 18332 19982 16474

224 2 sp N 2 harv 21517 19420 17189 15261

448 2 sp N 2 harv 20403 21403 18155 14417

896 2 sp N 2 harv 15770 15624 21519 17536

112 3 sp N 3 harv 17095 18335 18021 14397

224 3 sp N 3 harv 20021 18263 19381 16824

448 3 sp N 3 harv 19721 19723 18791 15682

896 3 sp N 3 harv 20779 17655 19163 15157

SED 6623 6693 5462 5531

Mean 19487 19393 19275 15799

Contrasts

1 harvest



2 harvests



3 harvests








1222 Thomason et al

ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS




y = 6E-06x + 02701 R2 = 00981

y = 2E-05x + 00491 R2 = 04984

y = 2E-05x - 00983 R2 = 07418

y = 1E-05x - 00186 R2 = 07683

0

005

01

015

02

025

03

035

04

045

05

10000 12000 14000 16000 18000 20000

Yield kg ha-1

Nut

rient

con

cent

ratio

n

P

Ca

Mg

S

y = 6E- 22

- 2

- 2 = 07418

- -

-

P




ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS



0

5

10

15

20

25

30

35

1998 1999 2000

Year

Yie

ld

Mg

ha-

1




wwwdekkercom)

0

5

10

15

20

25

30

35

1997 1998 1999 2000Year

Yie

ld

Mg

ha-




wwwdekkercom)

1224 Thomason et al

ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS










REFERENCES





















1991 22 1647ndash1660


ORDER REPRINTS















1226 Thomason et al









ORDER REPRINTS















1226 Thomason et al

















Documents

Switchgrass Response to Harvest Frequency and Time and ...nue.okstate.edu/Papers/Wade_2004.pdfSwitchgrass Response to Harvest Frequency and Time and Rate of Applied Nitrogen #