Dedicated Herbaceous Perennial Energy Crops

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1 Dedicated Herbaceous Perennial Energy Crops Rob Mitchell USDA-ARS Central East Regional Biomass Research Center Grain, Forage, and Bioenergy Research Unit Lincoln, Nebraska

2 Herbaceous Perennial Feedstocks Focus on switchgrass, the most advanced herbaceous perennial feedstock Optimizing sustainable yield will drive the economic feasibility Potential ecosystem services are critical Producer-driven acceptance is critical economics, familiarity, and committing land to longterm feedstock production

3 Other Herbaceous Perennials Prairie cordgrass Big bluestem Mxg Native polycultures

4 Land required to produce feedstock for a 50 million gallon cellulosic ethanol plant in a 25 mile radius Feedstock Yield tons/acre Acres % of Land Area 1 625, , , , , , ,500 5 A 50 million gallon plant requires 625,000 tons of feedstock/year at 80 gallons/ton.

5 Switchgrass: North American Native Ecologically functions as a monoculture

6 USDA in Lincoln, NE has Conducted Switchgrass Research Continuously Since 1936

7 Switchgrass is a Feasible Dedicated Energy Crop Productive Rapid & economically feasible establishment Proven management practices & producer acceptance Sustainable on marginal land Profitable for the Farmer Economically feasible at the field scale Protective of the environment Highly positive energy balance Sequester C

8 Rapid Establishment 5 May October tons/acre No-till seeded 57 acres into soybean stubble on 5 May 2006 Applied 1 qt. atrazine + 8 oz quinclorac/acre (Mitchell et al. 2010) Received 5 in of rain for the first 90-days after planting (40% of LTA) Mowed & sprayed with 1 qt./acre of 2,4-D to control broadleaf weeds in July Produced 2.5 tons/acre in the establishment year (50% of our yield goal) Seed quality & weed control are critical to economical switchgrass production

9 Proven Management 31 July 2007 (17 months after planting) 4 tons/acre 27 September tons/acre 2 tons/acre regrowth

10 Proven Management 18.5% moisture at harvest 7 August tons/acre 8 December tons/acre ~1 ton/acre regrowth Averaged over 4 tons/acre for the planting year and the first 2 production years

11 Producer Familiarity & Acceptance Equipment to plant, spray, harvest, bale, & transport is used in hay operations.

12 Switchgrass is Productive & Sustainable on Marginal Land Feedstock Yield, DM tons/acre Acres needed to grow 625,000 DM tons/year Percent of land in 25-mile radius LIHD 1 prairies , Managed native prairie , Shawnee switchgrass , Corn 150 bu/acre 111, Bioenergy switchgrass , Hybrid switchgrass , Low-input, high-diversity mixtures (Tilman et al. 2006). 2 Native prairie burned in late spring to promote WS grasses and suppress CS grasses (Mitchell, 1992). 3 Upland forage-type switchgrass cultivar released in Lowland Bioenergy-specific switchgrass in the cultivar release process. 5 F1 hybrid of Summer and Kanlow switchgrass cultivars that will likely reach field-scale production in 10 years (Vogel and Mitchell 2008).

13 Northern Plains Field Scale Production, Economics, Energy & SOC Annual Precipitation 10 locations for 5 years 165 acres seeded Seeded with commercial drills Dryland sites Harvested entire field with commercial hay equipment Farmers paid to manage fields as biomass energy crops On-Farm Production Trials: acre (6-9 ha) fields Annual Precipitation

14 Switchgrass is Economically Feasible Average yield for 10 farms was 2.4 tons/acre Average cost for 10 farms was $60/ton At 80 gal/ton, average farm gate feedstock cost for 10 farms was $0.75/gal Perrin et al. 2008

15 Switchgrass Average Annual Production Cost was $60/US Ton Fertilizer Applied $6.78 (11%) Harvest $14.72 (24%) Land Rent $26.91 (45%) Herbicide Applied $5.84 (10%) Planting $5.74 (10%) Costs annualized at 10%. Perrin et al. 2008

16 Economic Conclusions Land costs accounted for 45% of total costs Following best management practices is valuable Harvesting in the planting year reduced production cost by $11/ton Controlling weeds after planting reduced production cost by $11/ton Experience reduced production cost by $11/ton Perrin et al. 2008

17 Best Management Practices Pay Field near Bristol, South Dakota 5-year average yield of 4.2 tons/acre Average cost of $38/t including land & labor Farm gate feedstock cost was $0.48/gal Based on 80 gallons of ethanol per ton, each big bale equals 50 gallons of ethanol

18 Ethanol can Contribute to Energy and Environmental Goals Farrell et al Science Developed LCA model for corn grain and switchgrass (EBAMM) ( Estimated switchgrass inputs USDA on-farm switchgrass study Adapted the EBAMM model to determine net energy of switchgrass grown for bioenergy using actual agricultural inputs

19 Agricultural Inputs (GJ ha -1 ) Models Over-estimate Switchgrass 15 Energy Inputs Estimated Inputs 12 9 Actual farm inputs from 5-yr USDA study Other Machinery & Labor Herbicide 6 Seed Diesel 3 Fertilizer 0 Estab. Post. Farrell et al., 2006 Pimentel & Patzek 2005 Wang et al., 1999 Schmer et al. 2008

20 Switchgrass has a Positive Energy Balance Previous models over-estimate energy inputs for switchgrass production by as much as 2X Mean NEV (E out E in) was 21.5 Switchgrass produced 13X more energy as ethanol than was required as energy from petroleum (PER) Switchgrass produced 5.4X more renewable than nonrenewable energy consumed on marginal land when properly managed Schmer et al PNAS 105:

21 Switchgrass Sequesters Soil Carbon When Grown & Managed for Bioenergy C storage at Douglas, NE for 5-year period: 2.2 tons/acre increase in soil carbon in the top 12 inches of soil 0.44 tons C/acre/year 8.2 tons/acre increase in soil carbon in the top 48 inches of soil. 1.6 tons C/acre/year In the top 48 inches of soil at 4 NE sites, SOC increased at a rate of 2590 pounds of C/acre/year. Liebig et al Bioenergy Research

22 Hybrid switchgrass the next big step forward Strain Yield Tons/A Summer 6.1 Kanlow 7.1 Kanlow & Summer F1 s 9.4 Hybrid switchgrass can increase yield by 32 to 54% compared with parental lines (Vogel & Mitchell, Crop Science 48: , 2008). It will likely require 10 years to develop field-scale production systems for hybrid switchgrass.

23 Long-term Carbon Sequestration Study- Corn & Switchgrass, Mead, NE Experiment established in eastern NE in Compare switchgrass to no-till corn. Quantify C sequestration on cropland converted to switchgrass. In 2000, plots split and stover removed (50%) on split half of corn plots. Two switchgrass cultivars, two harvest treatments. Three N rates on switchgrass & corn. Results of first 5 years have been published, first 10 years currently being summarized.

24 Ethanol (l ha -1 ) Corn (Grain + Stover) vs. Switchgrass: Ethanol Production Switchgrass Corn Mean Year Varvel et al Biomass & Bioenergy

25 Yield (bu/acre) How can marginally-productive sites be identified? A field that yields 25% below the county level dryland yield is marginally productive. Saunders County Study (-28.2%) Mean

26 Based on 75 years of research (20 years for bioenergy), switchgrass is: Productive Forage types = 5 tons, Hybrids >9 tons Can be established rapidly & economically Has proven management practices Is accepted by producers Is sustainable on marginal land 12 yr old stands Profitable for the farmer Price similar to grass hay Protective of the environment Energetically positive PER = 13.1, NER = 5.4 Sequesters large quantities of C 2590 lb C/acre/year Feasible for rain-fed production east of the 100 th Meridian The most advanced ligno-cellulosic biofuel feedstock

27 Example of Where Energy Crops Fit A 50-million gallon Ethanol Plant Will Require: 125,000 acres of switchgrass assuming 5 tons/acre and 80 gallons of ethanol/ton of switchgrass. The Upper Big Blue NRD could grow 128,800 acres of switchgrass in pivot corners alone, enough for 1 50 MG plant at 5 tons/acre, or 2 50 MG plants at 10 tons/acre. Has 4 existing corn ethanol plants. 25-mile radius

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29 Large-scale switchgrass production can supply 100% of feedstock if Certified Seed is available to plant when biorefinery construction begins. Assuming 80 gallons of ethanol/dm ton, a 50-million gallon biorefinery will require 625,000 tons of DM per year. At an average yield of 5 tons/acre, 125,000 acres provides more than 130,000 tons of feedstock carryover to meet harvest, storage, & transport losses through Year 4. Year 1 Year 2 Year 3 Year 4 Plant Biomass Fields 65,000 60, Total Acres 65, , , ,000 Average Yield 2 tons/acre 3 tons/acre 4.5 tons/acre 5 tons/acre Total Feedstock Produced (tons) 130, , , ,000 Biorefinery Feedstock Demand (tons/year) 0 312, , ,000 Feedstock Carryover (tons) 130,000 62,500-62,500 0

30 Summary The Great Plains and Midwest are well-suited to switchgrass, Miscanthus and polycultures, with adequate marginal lands for feedstock production. Balancing biomass production, ecosystem services and producer acceptance will be major challenges for a diversified landscape in the new bioeconomy.

31 Bioenergy Publications Present Net energy of cellulosic ethanol from switchgrass. Proc. National Academy of Sciences. 105: Comparison of corn and switchgrass on marginal soils for bioenergy. Biomass and Bioenergy. 32: Opportunities and roadblocks in utilizing forages and small grains for liquid fuels. J. Ind. Micro. Bio. 35: Farm-scale production cost of switchgrass for biomass. Bioenergy Research 1: Cell wall composition and accessibility to hydrolytic enzymes is differentially altered in divergently bred switchgrass genotypes. Applied Biochemistry and Biotechnology 150: Managing and enhancing switchgrass as a bioenergy feedstock. Biofuels, Bioproducts, & Biorefining. 2: Heterosis in switchgrass: biomass yield in swards. Crop Science 48: Aged switchgrass seed lot s response to dormancy-breaking chemicals. Seed Technology Journal 30: Soil carbon storage by switchgrass grown for Bioenergy. Bioenergy Research 1: Switchgrass simulation at diverse sites in the northern Great Plains of the U.S. Bioenergy Res. 1: Isolation, characterization, & quantification of steroidal saponins in switchgrass. J. Ag. Food Chem. 57: Simulating switchgrass growth & development under potential and water limiting conditions. Ag. J. 101: Biofuels, bioenergy, and bioproducts from sustainable agricultural and forest crops. Bioenergy Res. 2: Registration of Warrior, Scout, and Chief indiangrass. J. Plant Registrations 4: Spatial and temporal effects on switchgrass stands and yield in the Great Plains. Bioenergy Res Switchgrass for biofuels. extension bulletin Efficient methods of estimating switchgrass biomass supplies. Bioenergy Res Grasslands, rangelands and agricultural systems. ESA Biofuels and Sustainability Report Herbicides for establishing switchgrass in the central and northern Great Plains. Bioenergy Res Quantifying actual and theoretical ethanol yields for switchgrass strains using NIRS. Bioenergy Res Switchgrass leaf area index and light extinction coeffecients. Agronomy Journal 103: Characterization of the arthropod community associated with switchgrass in NE. J. KS Ent. Soc. (In press). Field-scale soil property changes under switchgrass managed for bioenergy. Global Change Bio. Bioen. (In press).

32 Reports and Extension Publications Switchgrass for Biofuels extension is an educational partnership of 74 universities in the United States.

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