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June 10, 2007
Prairie power
Switch to switch grass for gas?
Evidence is growing that switch grass has an advantage over corn as fuel.
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Switch grass once fed vast buffalo herds on the Great Plains. Soon it may be used to feed your car.
Strong demand for corn to produce ethanol has pushed up corn prices, creating demand for cheaper alternatives. Switch grass is one such alternative, says USDA scientist Marty R. Schmer.
Among the advantages switch grass has over corn are "reduced use of fertilizers and pesticides, less soil erosion, greater biodiversity, and the ability to produce greater amounts of ethanol per acre and more ethanol overall," says Michael Griffin, executive director of the Green Design Institute at Carnegie Mellon University.
"Switch grass is grown without irrigation. Unlike corn, switch grass is a perennial crop and does not require fields to be plowed annually," adds the USDA's Paul Adler. "So, considering all phases of growing, processing and use, switch grass provides lower greenhouse emissions than corn."
Recently, USDA scientists reported the results of a five-year study to measure the amount of petroleum energyit takes to grow switch grass and convert it to ethanol, compared with the corn-based ethanol now in use. The study showed that making ethanol from switch grass instead of corn is much more energy-efficient.
-- John K. Borchardt
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