Comparative Nutrient Use Efficiency by Candidate Biofuel Crops


28 Feb 2010

2009 Annual Interpretive Summary

Current U.S. plans for energy security rely on the conversion of large acreages from food crop production to the production of cellulosic biomass in order to produce 86 billion gallons of biofuels, thereby reducing U.S. dependence on imported oil by 25% by 2025. Additionally, lands currently considered too marginal for intensive food production may be considered suitable for biofuel production, bringing highly erodible, nutrient-poor soils currently in conservation reserve programs back into intensive agriculture. In the U.S. Midwest, cropping systems may shift from the predominant corn-soybean base to a more varied array of species, including novel perennial grasses for which little agronomic and environmental impact data exist. Sustainable biofuels production with the concomitant protection and improvement of air, soil, and water resources requires a concerted effort by the scientific community to gain knowledge regarding the comparative production potentials and environmental impacts of candidate biofuel systems.

This multi-disciplinary team has initiated a study of the most promising biofuel crop species and management systems at Purdue University’s Water Quality Field Station (WQFS) Project team expertise combined with the unique WQFS capabilities for quantifying agro-ecosystem carbon, N, and water balance are permitting a quantitative assessment of candidate system net energy balance. Our overall goal is to develop a cropping system-level analysis of the potential for miscanthus, switchgrass, maize-based, and native prairie production systems to provide renewable fuel while protecting natural resources. Our hypothesis is that biofuel cropping systems differ in total yield and yield of structural and non-structural carbohydrate pools relevant to system profitability. In addition, we hypothesize that tangible differences in the water, N, and C economies of candidate systems exist and these differences will drive changes in soil and water quality. IN-25