|LAIRD, DAVID - IOWA STATE UNIVERSITY|
|OTTMAN, MICHAEL - UNIVERSITY OF ARIZONA|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 9/30/2010
Publication Date: 9/27/2011
Citation: Johnson, J.M., Arriaga, F.J., Banowetz, G.M., Huggins, D.R., Laird, D., Ottman, M.J., Wienhold, B.J. 2011. Crop residues of the contiguous United States: Balancing feedstock and soil needs with conservation tillage, cover crops, and biochar. In: Braun, R., Karlen, D., Johnson, D., editors. Sustainable Alternative Fuel Feedstock Opportunities, Challenges and Roadmaps for Six U.S. Regions. Ankeny, IA: Soil and Water Conservation Society. Available: www.swcs.org/roadmap.
Technical Abstract: Crop residues are among the cellulosic feedstocks expected to provide renewable energy. The availability of crop species and residue availability varies across the United States. Estimates of harvestable residues must consider all the residues produced during the entire rotation. Inclusion of fallow or low-residue producing crops requires that less feedstock be harvested. A reoccurring theme among the regions is that soil needs to be safeguarded against erosion and against loss of soil organic matter (SOM). First, highly erodible lands are categorically excluded from harvesting residues in all regions. The minimum of residue needed to meet soil needs is highly variable. Where sufficient residues are produced to meet soil conservation and SOM considerations harvest of a portion may be considered. Soil conservation practices include eliminating or at least reducing tillage to keep the soil covered, avoiding fallow and adding perennials, applying amendments (manure, biochar) and planting cover crops in areas with sufficient moisture. Calculating regional or national availability of residue feedstock is valuable for evaluating the feasibility of bioenergy production, however, on a field basis site-specific decision aids will be needed.