Bioeconomy Institute

Emerging industrial markets for liquid fuels derived from crop biomass are expected to create important economic opportunities for Iowa farmers and rural residents. However, existing strategies that rely exclusively on summer annual crops, such as corn, for biofuel production may also increase rates of soil erosion, degrade soil organic matter, reduce soil fertility, and increase requirements for energy-intensive fertilizers. To address these challenges, we are investigating two types of alternative cropping systems and associated management practices that might be used to generate large amounts of biomass while better protecting environmental quality. In one field experiment focusing on annual species, we are evaluating double-crop sequences composed of winter- and summer-adapted biomass crops. These double-crop sequences could be incorporated flexibly into existing corn-soybean systems and will provide soil cover and active root systems throughout the year, thus reducing potential soil erosion and nitrogen losses. In a second field experiment focusing on perennial species, we are comparing biomass production, carbon storage, and nutrient use efficiency by four grasses that show particular promise for biomass production. As an added dimension of the experiment, we are recovering nitrogen and other nutrients from grass biomass as it is processed into liquid fuel and assessing the impacts of applying the recovered material back to biomass production plots. Recycling nutrients between biorefineries and crop fields could significantly reduce economic and energetic costs associated with fertilizer use and promote decentralized agro-industrial networks.

Prinicpal Investigators:

Matt Liebman, Iowa State University

Robert P. Anex, Iowa State University

Kenneth J. Moore, Iowa State University

Andrew H. Heggenstaller, Iowa State University

Participating and/or Sponsoring Organizations:

ISU Plant Sciences Institute
Leopold Center for Sustainable Agriculture