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Estimated Costs - ($/a). $ 10. $35. $50. $8. $16. $40. Estimated Costs - (%). 6 %. 22 %. 31 %. 6 %. 10 %. 25 %. Low pH ? Or Nematodes ?. Un-Reacted Lime Due To Drought ?. Too Wet To Soil Sample ?. Seasonal Variation of pH. Lime (Calcium Carbonate) In Irrigation Water ?. - PowerPoint PPT Presentation
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Fertilizer & Soil Fertilizer & Soil ManagementManagement
2002 Cotton Production Workshop2002 Cotton Production WorkshopTifton, GATifton, GA
December 10December 10--1111
Glen Harris Glen Harris -- Extension AgronomistExtension Agronomist
University Of Georgia University Of Georgia -- TiftonTifton
TopicsTopics
EconomicsEconomics
pH and LimingpH and Liming
ManganeseManganese
TroubleshootingTroubleshooting
Nitrogen and PotassiumNitrogen and Potassium
Conservation TillageConservation Tillage
Poultry LitterPoultry Litter
Black RootBlack Root
2002 Field Trials2002 Field Trials
Estimated Costs - ($/a)
LimeFertilizerDefoliantInsecticideSeedHerbicide
$ 10
$50
$16$40
$8
$35
Estimated Costs - (%)
LimeFertilizerDefoliantInsecticideSeedHerbicide
6 %
31 %
10 %25 %
6 %
22 %
Fertilization StrategyFertilization Strategy
•• Soil TestSoil Test
•• Lime to pH 6.0Lime to pH 6.0
•• Apply Recommended P & K At PlantingApply Recommended P & K At Planting
•• Approx. 80 lb N/a in Split ApplicationsApprox. 80 lb N/a in Split Applications
•• Apply 0.5 lb/a Boron Foliar at First SquareApply 0.5 lb/a Boron Foliar at First Square
•• Tissue and/or Petiole TestTissue and/or Petiole Test
Low pH ? Or Nematodes ?
Un-Reacted Lime Due To Drought ?
Too Wet To Soil Sample ?
5
5.2
5.4
5.6
5.8
6
6.2
6.4
Aug Sep Oct Nov Dec Jan Feb Mar Apr May
Month
Soil
pH
Seasonal Variation of pH
Lime (Calcium Carbonate) In Irrigation Water ?
Poultry Litter Has a Slight Liming Capacity
0-1 in0-1 in
Eff ect of poultry litter on pH . . .Eff ect of poultry litter on pH . . .
Motta et al., 1998Motta et al., 1998
w/ o lit ter
w/ lit ter
1-2 in1-2 in
2-5 in2-5 in
5-10 in5-10 in
44 55 66 77pHpH
Conservation-Tillage = SOM = CEC = Less Lime ?
Soil Test (When Dry) Account For 1. When Sampled
2. Weather (Rainfall) 3. Previous Crop 4. Poultry Litter
5. When Limed Last
Manganese For CottonManganese For Cotton
•• UGA Dropped RecommendationUGA Dropped Recommendation
•• MnMn Deficiency on Cotton RareDeficiency on Cotton Rare
•• Maintain Soil Test Maintain Soil Test Mn Mn by pHby pH
•• Expensive to Build ST Expensive to Build ST Mn Mn All at OnceAll at Once
•• Look For Borderline FieldsLook For Borderline Fields
•• Consider Starter or Foliar Consider Starter or Foliar MnMn
•• Tissue Test To Confirm ProblemTissue Test To Confirm Problem
0
2
4
6
8
10
12
14
16
18
5.6 5.7 5.8 5.9 6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 7 7.1
Soil pH
Soil
Tes
t M
n (l
b/a)
Recommended Soil Test Mn with Different pH
TroubleshootingTroubleshooting
Likely Culprits Likely Culprits
•• Low pH Low pH
•• NitrogenNitrogen
•• PotassiumPotassium
•• SulfurSulfur
•• Boron ?Boron ?
Troubleshooting SamplingTroubleshooting Sampling
Prior To First BloomPrior To First Bloom
Soil and Tissue Sample Soil and Tissue Sample
“Good” & “Bad” “Good” & “Bad”
After First BloomAfter First Bloom
Soil, Tissue and Petiole Soil, Tissue and Petiole
Good” & “Bad” Good” & “Bad”
Nitrogen ManagementNitrogen Management
•• By Yield GoalBy Yield Goal
•• DrylandDryland vs. Irrigatedvs. Irrigated
•• Split ApplicationsSplit Applications
•• Sidedress Sidedress MaterialsMaterials
Potassium ManagementPotassium Management
•• All At PlantingAll At Planting
•• Anticipate ProblemsAnticipate Problems
•• Foliar vs. Foliar vs. Sidedress Sidedress ??
Results :1998Results :1998
•• Significant Significant
InteractionInteraction
•• AP/+F =AP/+F =
Best TreatmentBest Treatment
15931685
1524 1515
0
300
600
900
1200
1500
1800
AP/-F AP/+F SA/-F SA/+F
Foliar FertilizationFoliar Fertilization
•• Rescue vs. High YieldRescue vs. High Yield
•• High Boy vs. PlaneHigh Boy vs. Plane
•• Alone or With InsecticideAlone or With Insecticide
•• Source, Rates and TimingSource, Rates and Timing
•• N, K, B (maybe Zn or N, K, B (maybe Zn or MnMn))
•• Not P or Ca or Snake OilsNot P or Ca or Snake Oils
Conservation Tillage - FAQs
How Important Is A Good Start ? Should I Soil Sample Differently ? How Can Lime Work ? Can You Get Too Much Residue ? Should I Fertilize My Cover Crop ? Should I Adjust My N Rate on Cotton ? Should I Use A Starter Fertilizer Can I Use Poultry Litter ?
Nutrient stratification . . .Nutrient stratification . . .
P and K become horizontally bandedP and K become horizontally banded
0 50 100 150
Molboard
Chisel
No-till 0-5 cm
5-10 cm
10-15 cm
15-20 cm
(Karlen et al., 1991)
Soil P distribution af ter 11 years of t illage
P (mg/kg)
0 50 100 150 200 250
Molboard
Chisel
No-till0-2.5 cm
2.5-7.5 cm
7.5-15 cm
15-22.5 cm
22.5-30 cm
(Motta et al., 2000)
K distribution af ter 17 years of ti llage
K (mg/ kg)
Nitrogen Management . . .Nitrogen Management . . .Nitrogen Management . . .
N and cover cropsN and cover cropsN and cover crops
C : N RatioC : N RatioC : N Ratio
N
Available
NN
AvailableAvailable
N
Not Available
NN
Not AvailableNot Available
10:110:110:1 20:120:120:1 40:140:140:1
MineralizationMineralizationMineralization I mmobilizationI mmobilizationI mmobilization
Poultry Litter on CottonPoultry Litter on Cotton
•• 2 ton/a + 50 lb N/a 2 ton/a + 50 lb N/a SidedressSidedress
Basically = P Based PlanBasically = P Based Plan
•• 3 3 -- 4 ton/a If 4 ton/a If Blackroot Blackroot
•• Phosphorous IssuePhosphorous Issue
“Black Root” Update“Black Root” Update
First Observed in 1997 First Observed in 1997
Isolated to Poorly DrainedIsolated to Poorly Drained
Flatwoods Flatwoods Soils Soils
Disease Organism Never Disease Organism Never
Isolated Isolated
Gary Gary Gascho Gascho (1998) -(1998) -
Chloride Toxicity ? Chloride Toxicity ?
2002 Field Trials2002 Field Trials
Helena - Foliar N Helena - Foliar N
Agrotain Agrotain - UAN - UAN vsvs. Urea. Urea
GPFES - GPFES - Sidedress vsSidedress vs. Foliar K. Foliar K
AgriAgri-SC - Laurel sulfate-SC - Laurel sulfate
Stoller Stoller - Load- Load
GoemarGoemar - BM 86 - BM 86
Good Luck in 2003 !
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