1. Balancing Biomass for Bioenergy and Conserving the Soil Resource Jane Johnson USDA-ARS- North Central Soil Conservation Research Laboratory

2. USDA-ARS Introduction Energy paradigm is changing from petroleum to mixed renewable Energy paradigm is changing from petroleum to mixed renewable Sufficient energy available, but in diffuse form Sufficient energy available, but in diffuse form Can we be sustainable or at least minimize environmental footprint? Can we be sustainable or at least minimize environmental footprint? Can we balance food, feed, fiber and fuel? Can we balance food, feed, fiber and fuel?

3. USDA-ARS Outline Background Background Discuss roles of non-grain biomass Discuss roles of non-grain biomass Constraints for harvest rates Constraints for harvest rates Examples Examples Summary Summary

4. USDA-ARS Cellulosic biomass NRCS plant material center

5. USDA-ARS Cellulosic ethanol – sugar platform Cellulosic ethanol – sugar platform Thermochemical – controlled combustion Thermochemical – controlled combustion Gasification Gasification Dimethylether (DME) Dimethylether (DME) Replace natural gas Replace natural gas Pyrolysis Pyrolysis Bio oil, bio char, biogas Other bio-based products Other bio-based products Interest in biomass for bioenergy

6. USDA-ARS Agriculture – 998 million tons Perennial energy crops – 377 million tons Perennial energy crops – 377 million tons “Wastes” – 87 million tons “Wastes” – 87 million tons Grain – 87 million tons Grain – 87 million tons Crop residues – 428 million tons Crop residues – 428 million tons Corn stover – 256 million tons Corn stover – 256 million tons Forestry – 368 million tons (projected estimates; Billion Ton Report, Perlack et al 2005) Biomass for bioenergy

7. USDA-ARS Benefits Benefits Renewable Renewable Domestic Domestic Reduces release of fossil CO 2 Reduces release of fossil CO 2 Additional farm commodity Additional farm commodity Risks Risks Decreased surface residues Decreased surface residues Increased erosion Increased erosion Off-site nutrient and sediments Off-site nutrient and sediments Decreased SOM Decreased SOM Decreased productivity Decreased productivity Other – loss of winter cover, habitat Other – loss of winter cover, habitat Biomass harvest

8. USDA-ARS Primary roles of non-grain biomass Protect the soil from erosion Protect the soil from erosion

9. USDA-ARS Water USDA-NRCSMorris, MN 2003 Wakeeney, KS L. Kucerik, 2004 LaPorte, IN 2004 WindTillage MN, D. Reicosky http://www.umanitoba.ca

10. USDA-ARS Primary roles of crop biomass Protect the soil from erosion Protect the soil from erosion Provide C and other organic inputs to support the below ground ecosystem Provide C and other organic inputs to support the below ground ecosystem

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12. Primary roles of crop biomass Protect the soil from erosion Protect the soil from erosion Provide C and other organic inputs to support the below ground ecosystem Provide C and other organic inputs to support the below ground ecosystem Build and maintain soil organic matter/soil organic carbon Build and maintain soil organic matter/soil organic carbon

13. USDA-ARS Biomass management for Carbon (C) storage Storing C in soil – building humus Storing C in soil – building humus Nutrient cycling Nutrient cycling Water holding capacity Water holding capacity Improve soil aggregation Improve soil aggregation Maintain soil productivity Maintain soil productivity Remove CO 2 from atmosphere Remove CO 2 from atmosphere

14. USDA-ARS Biomass management for C storage C inputs > C outputs = increased SOC C Inputs C Inputs Crop above ground biomass Crop above ground biomass Crop root and their exudates Crop root and their exudates Manure Manure C Outputs C Outputs Respired C Respired C Erosion Erosion Tillage Tillage Leaching Leaching Harvest Harvest

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16. “The need to maintain soil productivity should be our first consideration and only, once this criterion has been met, should crop biomass be removed for alternative purposes.” William (Bill) Larson, 1979

17. USDA-ARS Minimum biomass inputs depends on Precipitation and temperature Precipitation and temperature Crop Crop Crop rotation Crop rotation Tillage Tillage Nutrient management Nutrient management Additional inputs Additional inputs Limiting constraint (erosion or carbon) Limiting constraint (erosion or carbon)

18. USDA-ARS USDA-ARS Renewable Energy Assessment Project (REAP) Team Locations

19. USDA-ARS REAP goals Determine how much biomass needs to stay on the land to protect soil resource Determine how much biomass needs to stay on the land to protect soil resource Compare short- and long-term economics of using biomass feedstock and soil organic input Compare short- and long-term economics of using biomass feedstock and soil organic input Provide recommendations and guidelines for sustainable biomass harvest Provide recommendations and guidelines for sustainable biomass harvest

20. USDA-ARS How much biomass needs to stay in the field? Prevent erosion Prevent erosion Sustain belowground ecosystem Sustain belowground ecosystem Build soil organic matter Build soil organic matter Sequester C Sequester C Maintain productivity Maintain productivity

21. USDA-ARS Constraints Erosion Erosion Reduces productivity Reduces productivity Degrades soil Degrades soil Degrades water quality Degrades water quality Amount as % surface cover Amount as % surface cover Soil organic matter Reduces productivity Reduces water holding capacity Degrades soil Contributed to increased atm CO 2 Total inputs

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23. Minimum inputs estimated by a simple linear relationship y is change in soil organic carbon change x is the amount of C (or biomass) input annually Larson et al., 1972; Paustian et al., 1997; Follett et al., 2005; Johnson et al., 2006

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26. Example, assumes conservation tillage and continuous corn

27. USDA-ARS Wilhelm et al., 2007, AJ

28. USDA-ARS Wilhelm et al, 2007 AJ

29. USDA-ARS Products: Guidelines for crop and soil management to ensure sustainable harvest Guidelines for crop and soil management to ensure sustainable harvest Predictive tools for crop biomass harvest Predictive tools for crop biomass harvest Tools to assess short and long-term trade- offs (environmental and economic) Tools to assess short and long-term trade- offs (environmental and economic)Outcome: Biomass energy industry based on sustainable management practices. Biomass energy industry based on sustainable management practices.

30. USDA-ARS Current projects Biomass removal study Biomass removal study Tillage: Tillage: No Till (Established 1995) No Till (Established 1995) No Till (Established 2005) No Till (Established 2005) Chisel Plow, spring disk Chisel Plow, spring disk Removal rates: 0, 50, 75 and 100% of rows Removal rates: 0, 50, 75 and 100% of rows Monitor: biomass produced, returned, soil carbon (0-100 cm), yield Monitor: biomass produced, returned, soil carbon (0-100 cm), yield

31. USDA-ARS Carbon Crop Study Established 2000, modified 2007 No tillage

32. USDA-ARS Related issues No perfect solution No perfect solution Fossil fuel – finite, huge environmental footprint Fossil fuel – finite, huge environmental footprint Water to grow crop Water to grow crop Water for conversion – energy platform dependent Water for conversion – energy platform dependent Off-site impacts of nutrients/pesticides Off-site impacts of nutrients/pesticides Habitat Habitat

33. USDA-ARS Its about the future: finding balance