Balancing corn stover harvest for biofuels with soil and water conservation

Abstract

The emerging cellulosic biofuel industry offers both challenges and opportunities for conserving soil and water resources in an agriculturally productive environment. Crop residues are North America's most important soil and water conservation resource and concurrendy will be the most important feedstock for the emerging cellulosic biofuels industry. This analysis of factors affecting water-induced soil erosion, soil carbon maintenance, and water quality in the emerging cellulosic bioenergy industry identifies a variety of critical issues likely to both direcdy and indirectly lead to greater degradation of these resources. Pressing issues are also identified for scientific research and for policy analysis. Research should determine more precisely the erosion rates and sediment delivery rates of different biomass cropping systems, determine the acceptable rates of residue removal for different crops and soils in the face of more frequent extreme rainfall events, describe how those removal rates vary spatially across the landscape, develop the harvest technology that removes residue at these rates, and develop a suite of conservation practices appropriate for use with crop residue harvest. Policy analysis should examine land ownership and management patterns to develop a policy environment in which conservation practices are encouraged, or at least not discouraged. A framework must be developed to oversee and insure that residue removal rates are not abusive to soil and water resources.