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Turning the switch

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Soft, swaying grasses on Oklahoma’s native tallgrass and shortgrass prairies once fed millions of bison. The majority of the prairie has been plowed under for row crops or development.

Now similar grasses used to feed livestock could also help provide transportation fuel, known as cellulosic ethanol, into the next several decades.

A multiuse, high-yield switchgrass is being developed from collaboration between the Samuel Roberts Noble Foundation, the University of Oklahoma and Oklahoma State University, as part of the Oklahoma Bioenergy Center.

The partners are also working to advance ethanol made from sweet sorghum and milo, plus biodiesel made from sunflower and canola oils.

Steven Rhines, Noble Foundation vice president, general counsel and director of public affairs, said the potential of switchgrass as a renewable alternative fuel source has been stymied by farmers’ reluctance to plant it instead of other crops, like corn or beans.

“Farmers and ranchers are not going to give up their land (to switchgrass),” Rhines said. “It’s really kind of tricky.”

Noble Foundation researchers are breeding the high-yield switchgrass.

“There really isn’t a market yet,” Rhines said. “Unless you can use it for some other purpose.” But he said farmers and ranchers would likely be far more interested if appropriate crop residues from the switchgrass could be fed to cattle.

He said it’s kind of like the chicken and egg syndrome — whichever came first.

“It’s an intriguing new niche.” Switchgrass has several distinct benefits over corn, which has been one of the primary materials used for ethanol and is often mixed with gasoline to make “gasohol.” It requires a fraction of the water and, unlike corn, it’s a perennial. Consequently, that reduces the crop’s carbon footprint through less machinery usage, Rhines said.

It’s a low-maintenance, hardy plant that can be harvested as a cash crop annually or semiannually for about 10 years before replanting is necessary. It grows fast and is relatively easy to grow, capturing solar energy and turning it into chemical energy that can be liquefied, gasified or burned. Farmers tend to plant it to control erosion.

“You can stress it and deprive it of water,” Rhines said. Instead of depleting the soil of certain nutrients and reducing fertility like many agricultural crops, switchgrass adds organic matter, packing it away in soil and roots.

Noble is studying switchgrass’ 30,000 genes. About 150 genes deal with drought alone.

The crop has produced up to a record 15 dry tons per acre at a test site in Alabama, with a dry ton measured after dehydration.

Another part of the same acreage, grown by Auburn University forage scientist Dave Bransby, averages 11.5 tons per acre a year for six years, which converts to about 11,500 gallons of ethanol per acre per year.

A 1,000-acre tract of land near Guymon, owned by the Oklahoma Bioenergy Center, will be the nation’s largest in-the-field research lab, according to the center.

The center is focusing on crop development and production, harvest, collection and transportation and formulating the most effective way to convert feedstock into biofuels that burn efficiently.

Switchgrass also tends to take a couple of years to get established and looks weak in its first year, which is deceiving, Rhines said.

“The first year it looks like a failure,” he said. “It has as much biomass underground as it does above ground.”

Production of ethanol from corn is about 2 billion gallons a year, but eventually switchgrass will likely provide some of that mix.

“For the first time in a long time, universities are working hand-in-hand,” Rhines said. “It was a natural fit.”

Efforts to develop cellulosic ethanol are funded in part by the 2008 Farm Bill, which contained the Biomass Crop Assistance Program and Bioenergy Program for Advanced Biofuels.

“It was created as an effort to take some of the risk away (for the farmers),” Rhines said.”

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