Balancing biomass for bioenergy and conserving the soil resource or Having your biomass and your soil too. Jane Johnson USDA-ARS, ARS, Morris, MN

Transcription

1 Balancing biomass for bioenergy and conserving the soil resource or Having your biomass and your soil too Jane Johnson USDA-,, Morris, MN

2 Grain Grain to ethanol Converts starch to glucose to ethanol In U.S. Mostly corn grain Domestic liquid fuel Only a small percent of total Environmental risks with corn production N-fertilizer intensive USDA-

3 Cellulosic biomass USDA-

4 Six biorefinery projects to receive DOE funding Abengoa Bioenergy Biomass; ALICO, Inc.; BlueFire Ethanol, Inc.; Broin Companies; Iogen Biorefinery Partners, LLC; and Range Fuels. KS; LaBelle,, FL; CA; Emmetsburg, IA; Shelley, ID; Soperton, GA. non-food based biomass such as agricultural waste, trees, forest residues, and perennial grasses, 130 million gallons of cellulosic ethanol per year USDA-

5 Biomass harvest Benefits Renewable Domestic Reduces release of fossil CO 2 Additional farm commodity Risks Decreased surface residues Increased erosion Decreased SOM Decreased productivity Nutrient removal USDA-

6 How much is enough To minimize erosion Maintain or increase soil organic matter/soil organic C Nutrient cycling Support soil ecosystem Other services? USDA-

7 Tillage Wind Water Pace of erosion LaPorte, control IN 2004 has slowed as we approach the goal of managing to T. However, 1.8 billion tons of soil are still lost from cropland annually. 120 million acres Wakeeney, of cropland KS are eroding L. Kucerik, 2004 at a rate greater than T. soils.usda.gov/sqi/ MN, D. Reicosky USDA- Morris, MN 2003 USDA-NRCS

8 How much? If controlling for wind and water erosion T 20% - corn stover and wheat straw without exceeding T values based on yield values, 37 states (central, midwest and eastern) Nelson, times the US motor ethanol in 2000 About 2% of motor fuel in 2000 Wilhelm et al., 2004 USDA-

9 Go beyond T - Manage for C Managing all cropland for T, annual soil loss would decline by 0.85 billion tons. Save $16 billion Managing all cropland for C (carbon) (SCI>0), soil loss would decline by 1.29 billion tons. Save $24 billion USDA- soils.usda.gov/sqi/

10 Biomass management for Carbon (C) storage Storing C in soil building humus Nutrient cycling (N, P, K, S and micro) Water holding capacity Improve soil aggregation Maintain soil productivity Remove CO 2 from atmosphere USDA-

11 Climate and weather interactions Climate and weather impact rate of residue conversion to SOC and retention of SOC after Brady (1974) Average temperature increases from north to south -SOM decreases- (primary effect of temperature) USDA- Effective moisture increases from west to east -SOM increases- (primary effect of NPP)

12 Wilhelm et al., 2007, AJ Stover to retain (Mg ha -1 ) Soil Organic Carbon Water Erosion Wind Erosion Moldboard plow 5.25 Continuous corn No or conserv. tillage USDA Moldboard plow 7.90 No or conserv. tillage Corn-soybean Stover to retain (ton acre -1 )

13 Harvesting stover or other straws harvest more than C from field Nutrients in corn stover and wheat straw based on 2006 corn yields in the United states Nutrient Corn Wheat (lb Acre -1 ) N P 2 O K 2 O Ca Mg S Cu Mn Zn (courtesy J. Hatfield; USDA-) USDA-

14 USDA- Renewable Energy Assessment Project (REAP) Team Locations Determine how much biomass needs to stay on the land Compare short- and long-term economics of using biomass feedstock and soil organic input Provide recommendations and guidelines for sustainable (environmental and economic) biomass harvest USDA-

15 Take home message Increasing demands are being placed on our soils It is critical to protect our soil resource to meet the increasing demands of food, feed, fiber and fuel. Energy consumption must also be curtailed. USDA-

16 Acknowledgements Wally Wilhelm, USDA- -Lincoln, NE Dave Archer USDA- -Mandan, ND Ron Follett USDA- -Fort Collins, CO Jerry Hatfield USDA- -Ames, Ames, IA Doug Karlen USDA- -Ames, Ames, IA Don Reicosky USDA- -Morris, MN USDA- Photo: Courtesy W. W. Wilhlem