Switchgrass for Biomass Energy

Switchgrass for Biomass EnergyRob Mitchell

USDA-ARSGrain, Forage, and Bioenergy Research UnitLincoln, Nebraska

BackgroundEstablishmentProduction, Harvest and StorageSwitchgrass Production EconomicsSwitchgrass Energy ProductionLand Requirements and FeedstocksAnswer Biorefinery QuestionsWhere are We Going?

Native to Tallgrass PrairieEcologically functions as a monoculture

Switchgrass Biomass EnergyCurrent Goals & ResearchGoalsFull establishment in 1 year with 50% yieldBe at full production (5 t/a) second yearGoal of 10 t/a in Midwest; increase ethanol yield/tonFully document environmental benefitsTools and ProductsWeed control, no-till planting, seed qualityBreeding - Biomass specific cultivars & F1 hybrids, improved conversion, NIRSMolecular biology, cell walls, conversion & seed qualityC sequestration, entomology

to this?How do you get from thisEstablishing Switchgrass

Is switchgrass feasible for the area?Suitable for dryland corn = suitable for switchgrassPlant 2 to 3 weeks either side of optimum corn planting dateDevelop a good seedbedNo-till seed into soybean stubbleClean till and pack to leave a faint footprintUse high quality certified seed of adapted materialPlant at least 30 PLS per ft2 to 1/2 deepManage weeds ASAP!Pre-emergent application of 1 qt. of atrazine plus 8 oz of quinclorac/acreMow or spray broadleaves with 1-2 qt./a of 2,4-D in summerSpend money on quality seed & weed controlSwitchgrass Establishment Recipe

Switchgrass seedling morphology, seedbed firmness, and planting depthSeedlings develop adventitious roots at soil surface not at seed.Seed < 1/2 deepSoft seedbed with packer wheel depressionThe seed is too deep and will have problems emergingPlanting depth} = 1/2.} = 1/2Seed First rain fills the depression} = 1Seed .

No-till seeded 57 acres into soybean stubble on 5 May 2006Pre-emergent application of 1 qt. of atrazine plus 8 oz of quinclorac/acreReceived 5 in of rain for the first 90-days after planting (40% of LTA)Mowed & sprayed with 2 qt./acre of 2,4-D to control broadleaf weeds in JulyProduced 2.5 tons/acre near Mead, NE in the establishment year (50% of our yield goal)Seed quality & weed control are critical to economical switchgrass productionWorst-Case Scenario for Switchgrass Establishment6 October 20062.5 tons/acre5 May 2006

Worst-Case Scenario for Switchgrass Establishment27 September 20074 tons/acre2 tons/acre regrowth31 July 20074 tons/acre

Worst-Case Scenario for Switchgrass Establishment17 October 20085-6 tons/acre~1 ton/acre regrowth7 August 20086 tons/acreAveraged over 4 tons/acre for the planting year and the first 2 production years

Switchgrass Harvest & Storage

Switchgrass Harvest & Storage

24% DM loss in 12 months3 or 4 wraps reduces spoilageChopping reduces densityBig squares rapidly degrade outsideSwitchgrass Harvest & Storage

Major Questions for Perennial Herbaceous Bioenergy CropsCan perennial herbaceous biomass energy crops be produced at a cost which makes their use for biomass energy economically feasible? (Initial goal was to compete with $35/barrel oil.)Are perennial biomass energy crops net energy positive? New Question: Are they greenhouse gas neutral or negative?

31-33 Annual Precipitation15-17 Annual Precipitation2000-2005On-Farm ProductionTrials: 15-20 acre (6-9 ha) fields Cooperating farmers paidto manage fields as biomass energy crops.Northern Plains Field Scale Production and Economics Trial

USDA switchgrass study10 locations for 5 years165 acres seededSeeded with commercial drillsDryland sitesHarvested entire field with commercial hay equipment

Switchgrass Average Annual Production CostsPerrin et al. 2008Costs are annualized at 10%.

Cost Item$/Acre$/TonPlanting12.745.74Herbicide Applied12.955.84Fertilizer Applied15.046.78Harvest32.6514.72Total Operating Costs73.3833.08Land Rent59.7026.91Total Cost133.0859.99

Previous Switchgrass Producer vs. New Crop ProducerExperience helped producers reduce production costs by $10.86/ton during the 5 production years.Perrin et al. 2008

Five Year Average Cumulative CostsTotal costs $/tonCosts (no land $) $/tonExperienced (2)$43.13$26.42New crop producer (8)$69.16$37.28

Extension Efforts Will Pay DividendsField of Jerry Roitsch near Bristol, South Dakota5-year average yield of 4.2 tons/acreAverage cost of $38/t including land & laborFarm gate feedstock cost was $0.48/galBased on 80 gallons of ethanol per ton, each big bale equals 50 gallons of ethanol

Paramount Herbicide vs. No Paramount in Establishment YearApplying Paramount in the establishment year reduced production costs by$11.27/ton for 5 production years, a $124/a return on a $20/a investment.Perrin et al. 2008

Five Year Average Cumulative CostsTotal costs $/tonCosts (no land $) $/tonParamount used (4)$44.06 $28.35No Paramount (6)$77.22$39.62

Year 1 Harvests vs. No Year 1 Harvest ComparisonsPerrin et al. 2008Harvestable yields in the establishment year reduced production costs by$10.71/ton over the 5 production years.

Five Year Average Cumulative CostsTotal costs $/tonCosts (no land $) $/tonYear 1 Harvest (3)$44.22 $27.61No Year 1 Harvest (7)$72.41$38.32

On-farm Switchgrass Production in the Great Plains EnergyPrevious models over-estimated the energy inputs for switchgrass production by as much as 2XSwitchgrass produced 13X more energy as ethanol than was required as energy from petroleumSwitchgrass produced 540% more renewable than non-renewable energy consumed on marginal land when properly managedSwitchgrass biofuel production systems are economically feasible, and energetically positive on marginal cropland in the central USA east of the 100th MeridianSchmer et al. 2008 Proceedings of the National Academy of Science

Man-made prairiesOne locationSmall-plotsHand-seededIrrigated during establishmentHand-weededHand-harvested - 10cm wide strips

USDA switchgrass study10 locations67 ha seededSeeded with commercial drillsDryland sitesHarvested entire field with commercial hay equipment

Managed switchgrass produced 97% more ethanol yield than man-made prairiesTilman et al., 2006USDA study

Chart1

2376276833714434433535180180

LIHD1406LIHD00

LI-SW475LI-SW00

Corn grain (NGP)3066Corn grain (NGP)300300

Low yielding farms

Mean yield

High yielding farms

Ethanol Yield (L ha-1)

Ethanol

Ethanol YieldNet Energy Value

Estab.2345MeanHarvest YearEstab.2345Mean

LocationL ha-1LocationMJ L-1

Lawrence, NE0174619942708.382376.042206Lawrence, NENH20.121.022.121.921.3

Douglas, NE02311.114943350.142868.822505.92Douglas, NENH20.919.922.321.721.2

Atkinson, NE05127372765.6821011529Atkinson, NENH17.618.722.421.720.1

Crofton, NE0109318412765.682395.142024Crofton, NENH20.220.422.522.221.322422.9

Ethan, SD015053048.362635.82330.22379.86Ethan, SDNH18.821.522.821.221.1589522.9

Huron, SD173028882517401121012650Huron, SD23.123.622.423.221.422.7172123.11

Highmore, SD003220.263170.61413.42601.42Highmore, SDNHNH22.522.923.222.950917.6

Bristol, SD152831093793435546223482Bristol, SD22.020.022.822.623.722.2152022.0

Streeter, ND01738.11925.283178.242330.22293Streeter, NDNH23.022.121.921.122.0

Munich, ND33217573117319426362207Munich, ND14.821.521.621.922.720.533114.8

Mean35916662369321325172388Mean20.020.621.322.522.121.5

173720.14

229920.89

6283.447631579108720.25116243.781184211116.2437811842

149718.75

287323.62

309319.962

172922.974

174821.529

year 3

198420.969

148619.863

73318.672

183220.426

3032.421.510

250422.442

3203.422.493

377322.820

1915.222.064

310121.616

year 4

2694.222.138

3332.622.273

2751.222.435

2751.222.481

262222.805

399023.172

315422.935

433222.613

3161.621.928

317721.899

year 5

2363.6021.88

2853.8021.71

2090.0021.67

2382.6022.16

2318.0021.20

2090.0021.39

1406.0023.17

4598.0023.73

2318.0021.14

2622.0022.66

Tillman

LIHD

PV

224-9.7

5609.9

78513.8

112116.5

168118.9

224219.8

246620.3

356421.3

392321.5

423721.6

446121.7

466321.8

504421.9

526822

589622.1

Ethanol

00000

00000

00000

00000

00000

0000

0000

0000

0000

0000

0

Establishment

Year 2

Year 3

Year 4

Year 5

Ethanol Yield (L ha-1)

NEV (MJ L-1)

Sheet4

Sheet4

3.49160029868.675442076215.336408223416.180257604415.893293201415.68.20.7

12.339636877310.313779212614.856361377615.824138420415.737378326715.610.11.4

9.725454322812.548046510116.450400400415.843059601315.611.52.5

3.34340356516.018424962314.806616559715.407869489814.485707887215.612.34.1

8.461918922216.487287346716.415248863415.525511324315.612.65.3

16.320783988614.730770430416.889303944614.235049268215.612.76.2

15.254652652113.893874536216.734644887414.340253313315.612.86.9

8.578606338316.80781659817.113186090516.992552954415.612.97.4

14.796463782814.907603663516.189297540915.377844066515.612.97.8

15.717420629116.104076983515.943820829115.6138.2

GREET (10)

EBAMM (8)

Pimentel and Patzek (13)

Ethanol Yield L ha-1

Ethanol (MJ)/Petroleum (MJ)

Sheet1

23.111046880420.968977107322.137734388721.877882463222.91

17.613179773119.86