To: combjelly who wrote (316358 ) 12/21/2006 9:34:56 PM From: tejek Read Replies (1) | Respond to of 1573504 Medley of prairie grass may supplant corn in ethanol Researchers say prairie grasses can produce more net energy per acre than corn<?I> By MIKE MEYERS MCCLATCHY NEWSPAPERS 12/17/2006 MINNEAPOLIS - World demand for fuel and food is projected to double in the next 50 years. Now, researchers have concluded that corn may not be up to the task of filling both stomachs and gas tanks. "Unless we produce food and biofuel in an efficient manner, they will be directly competing with each other," said David Tilman, regents professor of ecology at the University of Minnesota. "We will have high prices for both." University researchers, led by Tilman, think they've found a solution - supply the facilities that make ethanol with a diverse mixture of prairie grasses instead of corn. The grasses not only can produce more net energy per acre than corn but they also act as a sponge for greenhouse gases before being harvested, soaking them out of the air and into their roots and surrounding soil, the researchers found. The last trait could prove an economic bonus for farmers if businesses one day are able to cash in "credits" for removing greenhouse gases from the air, as many predict. Clean air credits already are traded in Europe. Nearly 100 ethanol plants consuming corn have sprung up across the country. A director of the Minnesota Corn Growers Association has warned that supplanting corn with grasses would be a complex, costly task that could take years. But in an interview, Tilman contended that prairie grasses could represent a new cheap-to-produce cash crop that would be more of an opportunity than threat to farmers. In a cover story published in Science Magazine, the researchers reported that a field planted with a medley of prairie grasses and flowering plants packed more than triple the energy of single-variety grasses. Their study also estimated that mixed prairie grasses grown on marginal farmland would yield 51 percent more energy per acre than corn cultivated on fertile land. But the benefits didn't end there, the researchers said. The diverse mixture of prairie grasses was grown on depleted land without the fertilizers and pesticides commonly used on corn crops. Because the grasses require almost no maintenance, less gasoline and diesel fuel would be burned tending to fields. And because prairie grasses act like traps for greenhouse gases, greenhouse gas reductions are six to 16 times greater from using mixed prairie grasses than from using corn-based ethanol, the researchers estimated. "Unlike all other biofuels proposed so far, these are unique," Tilman said. Harvesting and processing a hectare (about 2.5 acres) of grasslands annually produces about three-tenths of a metric ton of carbon dioxide, the researchers calculated. But in the first 10 years the crop grows, the grasses absorb 4.4 metric tons of carbon dioxide. In other words, the prairie grasses absorb about 14 times more greenhouse gas than is released in producing grass-based fuel. Tilman led a team of researchers studying grass crops planted at the Cedar Creek Natural History Area in central Minnesota. President Bush has touted research into making ethanol from switchgrass. But the researchers found that a single species of grass is far less promising as material for ethanol production than is a blend of prairie grasses. They studied 16 varieties. "Switchgrass is very productive when it's grown like corn, in fertile soil with lots of fertilizer, pesticide and energy inputs, but this approach doesn't yield as much energy gain as mixed species in poor soil, nor does it have the same environmental effects," Jason Hill, a post-doctoral researcher who worked with Tilman, said in a statement. Spokesmen for the ethanol industry and corn growers offered divided reactions to the idea of creating ethanol from prairie grass. "Ethanol is ethanol," said Bob Dinneen, president of the Renewable Fuels Association in Washington, D.C. "We don't have a bias as to what the feedstock is. The marketplace is going to determine what feedstock will prove to be the most economical in the future." The technology to make ethanol from grass is advancing rapidly, Dinneen added. But he raised doubts about whether grasses will supplant corn as a major ingredient in producing ethanol. "I'm not smart enough to know what technology will win out or which feed stocks will be the most economical," he said. Ron Obermoller, a corn and soybean grower in Brewster, Minn., said he believes corn will remain king in ethanol production. He owns shares of two Minnesota ethanol plants and is a director of the Minnesota Corn Growers Association. For instance, he doubts the government ever will free farmland set aside for conservation to grow prairie grasses for harvest. "I'm not sure we've got idle land," he said. "If you harvest all, that's a problem." Conservation land is home to ducks and pheasants and provides hunting grounds and extra revenue for farmers, Obermoller said. On the other hand, if the economics are favorable, he sees benefits in grass cultivation - even for farmers who now grow corn. While the price of corn is high enough to justify the cost of shipping it great distances, the market prices of prairie grasses are likely to be much lower, he said. Shipping costs would dictate clustering ethanol production plants near the grass fields. "Instead of having big plants, we will have hundreds of smaller plants," he said. "That gives the farmers the chance to invest locally." buffalonews.com