The development of renewable sources of fuel and power is a high national priority for several reasons:
Conservation of finite fossil fuel resources
Mitigation of climate change related to rising levels of atmospheric CO2
Reduction of US dependence on imported fuels
The agricultural sector is already contributing renewable fuels through corn grain ethanol and soy biodiesel production, but there is already a broad array of both food and non-food uses for corn and soybeans, so increased production of biofuels from the agricultural sector must ultimately come from non-grain (cellulosic) sources, such as corn stover. Stover, the stalks and leaves of the corn plant, is typically returned to the soil, where it is decomposed by bacteria and fungi, releasing nearly all of its carbon as CO2 and returning nutrients to the soil. Researchers at USDA-ARS laboratories in Pennsylvania and Illinois are developing processes to convert corn stover to fuels of various forms. Here in Minnesota, we are conducting research to examine the environmental impacts of corn stover removal, i.e. – can we develop farming systems in which we harvest both grain and stover without adverse impacts, such as increased erosion, decreases in soil organic matter, or impaired water quality. This research is being conducted in conjunction with colleagues at a number of ARS sites throughout the country, as a part of the REAP project. In Minnesota we are testing the ability of farming practices such as cover cropping and companion cropping to prevent these negative consequences. We are also measuring changes in soil carbon levels under continuous corn with simultaneous harvest of grain and maximum stover removal, using an experimental combine developed at Iowa State University as part of a multi-state collaborative Sun Grant initiative. For more information contact Dr. John Baker (John.Baker@ars.usda.gov).