High on Grass
UNO Professor studies prairie grasses
as untapped source of biofuel
By Greg Kozol
When visitors take in the vista of UNO’s 320-acre Glacier Creek Preserve north of Omaha, they’re getting a glimpse of the past.
“You can see nothing but prairie,” UNO Biology Professor Tom Bragg says. “What we're looking at is probably the way it was in the 1800s.”
But the preserve also might be providing a look at the future.
So says Bragg’s colleague Tim Dickson. Also a biology professor, Dickson believes the tallgrass prairies of Nebraska and other Midwestern states can not only help prevent erosion and fight pesty insects, but they also might one day fill up our gas tanks and help America gain energy independence.
“The idea that you can have your cake and eat it too, to have these landscapes that have environmental benefits and have a commodity that you can sell, is kind of appealing,” Dickson says. “People are looking for alternatives.”
Dickson has studied the advantages of planting switchgrass and other types of prairie grass. His research, published with 16 other authors by the National Academy of Sciences, primarily examined ecological benefits of switchgrass as opposed to crops like corn.
The research could open the door to increased use of switchgrass as a biofuel. Right now, corn and soybeans are widely used because the seeds can be easily converted into biofuel. Engineers are trying to develop ways to make switchgrass a viable option, but widespread commercial production remains elusive.
“It's kind of the difference between eating corn and eating grass,” Dickson says. “Corn is a lot easier to break down than grass.”
What Dickson's research shows is that switchgrass offers environmental advantages — even if an immediate cash benefit doesn't exist from biofuel production.
Consider the soybean aphid, a soft-bodied insect that feeds on one of the largest crops in the Midwest. Making matters worse, the aphid reproduces prolifically, causing significant economic damage as an infestation spreads during the growing season.
Dickson's research found that switchgrass, a perennial with plenty of stumps and plant litter left over during the winter, creates a perfect natural habitat for animal and insect species. Some of those species happen to be predators of the soybean aphid, allowing farmers to control the pest with less reliance on insecticides.
“What we found is in some ways not surprising,” he says. “The number of species in perennial grasslands is a lot higher than the number that exists in corn.”
In addition, switchgrass reduces greenhouse gas emissions through microbes in the soil that prevent the release of methane. Switchgrass also prevents erosion, which is important for marginal lands planted with corn during the ethanol boom.
“Switchgrass can grow in degraded soil, poor soils,” Dickson says. “It tends to be more productive in richer soils.”
Much of Dickson's research centered on fields in Michigan and Wisconsin. But there’s plenty to study at UNO’s Glacier Creek Preserve, which has doubled in size in recent years to 320 acres. It boasts a seas of prairie grass, birds, butterflies and numerous other species — all just 12 miles from UNO's campus.
Visitors, says Preserve Director Bragg, “drop off the road and can't believe they're looking at grassland all around them.”
The future could bring a 228-acre expansion, if enough funds can be raised. Bragg calls the preserve an “under-the-radar” asset that allows research opportunities on prairie management, small mammals, bird populations and soil management.
And, no, there isn't a glacier on the site, although the preserve does have a stream with that name. “We needed a good name for a grant,” Bragg says.
Dickson plans to conduct future research at Glacier Creek to examines what types of prairie grass species grow best on marginal lands. This is important, Dickson says, because switchgrass is necessary for controlling erosion and it will be relegated to poorer soil as long as corn and soybeans are more profitable.
“Once farmers can convert switchgrass and prairie grass to ethanol, farmers have a real benefit to sell it as biofuel,” he says.
The current research reminds Dickson of the days when he found himself at “ground zero” of the ethanol debate. Corn-based ethanol generated enormous benefits for rural areas and energy consumers, but at a cost that included increases to erosion and food prices.
Dickson hopes biofuel made from switchgrass will create similar upsides, but without as much baggage.
“There are a lot of issues with growing corn ethanol because of increased commodity prices and increased erosion,” he says. “I think there is definitely a backlash.”