Local News

by Bill Hudson
Zimmerman, Minn. (WCCO) ― In a cold, dusty Zimmerman, Minn. warehouse, the seeds of our energy future are being separated from the chaff. At the Prairie Restoration Company, winter is spent sorting and sacking the seeds of native prairie plants.

Could it be that these prairie grasses will become the crop that breaks our nation's oil addiction?

According to the University of Minnesota's David Tilman, a research professor at the College of Biological Sciences, recent findings are promising.

"If we really want to have a sustainable energy supply corn ethanol is not going to give us long term sustainability," said Professor Tilman.

Cutting edge agricultural research has long been a hallmark of the University of Minnesota. In 1970, Dr. Norman Borlaug won the Nobel Peace Prize for his "green revolution" that led to agricultural practices to help feed a starving world. Today, Tilman's work could help fuel it.

"I do see the parallels," recounted the professor as he explained his research into growing a diverse mix of native prairie plants.

For the past dozen years, Tilman and his graduate students have grown plots of diverse prairie grasses on the Cedar Creek Research Station in Anoka County. The diverse varieties of plants could become the biomass that would take the place of corn, used to make ethanol.

"By analogy, we're trying to find highly efficient ways to produce energy. Our work suggests it's different than the efficient ways to produce food," Tilman said.

It's different when you consider that our current farming practice is one of monoculture, meaning farmers plant vast acres of a single crop -- like corn and soybeans -- which are highly tilled, fertilized, irrigated and sprayed with pesticides.

This model grew out of the "green revolution," when agricultural efficiencies were needed to satisfy the world's growing hunger.

Tilman's research now shows that the opposite will be true when it comes to growing crops for fuel. He and his research team discovered that land planted with a highly diverse mix of prairie grasses and plants will actually produce more than twice the bioenergy of the same land planted with any single species, including Corn.

"We were getting as much and in fact, in some conversion processes, more energy per acre on marginal land than we get with current corn production," Tilman explained.

Perhaps even more promising are the findings concerning greenhouse gasses. Native prairie grasses and plants appear to drastically reduce greenhouse gasses, findings recently published in the journal "Science."

By capturing airborne carbon dioxide and returning it to the soil, prairie grass biofuels are essentially carbon negative.

"We can make a fuel which, when you get done burning it, you have less CO2 in the air than before," said Tilman. "It sounds impossible but it's because of what these high diverse prairies do as they restore the soils."

The idea is already taking root in Blue Earth County, where the Madelia Project aims to plant vast acres of prairie to help reduce farm chemical runoff and provide a struggling rural economy another cash crop.

"You might get your bioenergy payment ... but then also get a carbon payment, nitrogen and phosphorus reduction payments," said Linda Mehlke, who directs the program. "That's how economically we can make bioenergy crops work."

Mehlke made it clear that the goal isn't to get farmers to switch from corn and beans into prairie grasses -- that would cause serious harm to the world's food supply. Rather, the idea is to convince farmers to plant prairie on their less productive, marginal acres.

"We think it's a model that can work, and it can work for farmers, for communities and for society in general," said Mehlke.

Tilman feels we have little choice but is also well aware of the challenges that remain. He said more research needs to be done to find enzymes that can efficiently break down the cellulosic fibers of prairie grass.

He's confident that the process will become economically viable in the next five to seven years.

"There just isn't enough corn," he said. "In fact, if you took all the corn we grow in the U.S. now and convert that corn to ethanol, that ethanol could displace just 12 percent of the energy in the gasoline we burn right now."

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