Mixtures of plants native to prairies can give a better energy return as biofuel than corn and soybeans do, a new study finds. Biofuel production from grassland plants would also result in lower emissions of carbon dioxide and reduced pollution from agricultural chemicals.
Corn-grain ethanol and soybean biodiesel are starting to replace some gasoline and petrodiesel (SN: 7/15/06, p. 36: Farm-Fuel Feedback: Soybeans have advantages over corn). However, corn and soy crops need large amounts of pesticides, water, and fertilizers.
Ecologist David Tilman of the University of Minnesota in St. Paul and his colleagues determined the resources required for and energy gained from biofuels m