Magazine article Science News

Farm-Fuel Feedback: Soybeans Have Advantages over Corn

Magazine article Science News

Farm-Fuel Feedback: Soybeans Have Advantages over Corn

Article excerpt

A new analysis of two commercial biofuels finds that while both provide more energy than they consume, soybean biodiesel gives more bang for the buck than ethanol made from corn does.

Corn-grain ethanol and soybean biodiesel are the two major alternative transportation fuels in the United States. The biofuels can replace gasoline and diesel, respectively. A team of Minnesota ecologists and economists set out to add up all the energy and environmental costs and benefits of the two food-based biofuels.

The researchers included the energy required to grow the crops, run farm machinery, manufacture fertilizers and pesticides, transport the crops, and transform the raw material into fuel. They also considered the environmental impact of the added fertilizers and pesticides.

Both biofuels yield energy, but with corn-based ethanol, "it takes so much energy to grow the corn and convert it into a fuel, you don't gain very much energy in the overall process," says ecologist David Tilman at the University of Minnesota in St. Paul. While ethanol provides 25 percent more energy than it consumes, the energy gain for soybean biodiesel is 93 percent. Various steps in making ethanol, such as distillation, are energy intensive.

Corn also needs more fertilizer and pesticides than soybeans do. Per unit of energy gained, biodiesel requires 1 percent of the nitrogen, 8.3 percent of the phosphorus, and 13 percent of the pesticides that corn-derived ethanol does. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.