Mixed Prarie Grasses Make Better Biofuel than Corn or Soybeans

Researchers at the University of Minnesota have announced the results of a study calling mixed prairie grasses a better source of biofuel than the more prevalent corn ethanol or soybean biodiesel. Although the Department of Energy says it costs about five times more to make fuel from grasses than it does to make it from corn, prairie grasses have a number of distinct advantages.

Unlike corn, for example, mixes of these grasses grow willingly on poor, sandy soils. They also grow "with almost no input;" they require no pesticides, no fertilizer, and no irrigation. Additionally, they are "carbon-negative," meaning that "by the time the whole life cycle is done and they are combusted, there is less carbon dioxide in the atmosphere than there had been before." This is because prairie grasses bury much of the CO2 they harvest from the air into the soil and in their deep, permanent roots, leaving much of it in the ground after the grasses are harvested. Corn and soybean biofuels, on the other hand, are "carbon-positive."

Researchers estimate that growing mixed prairie grasses on all of the world's degraded land could produce enough bioenergy to replace 13% of global petroleum consumption and 19% of global electricity consumption.