Biofuel Potential of Grass Probed

FARGO - Jun 8/07 - SNS -- North Dakota State University (NDSU) researchers are probing the economic potential of perennial grasses for us in the production of biofuels.

In spring 2006, the researchers planted seven species of perennial grasses to study which might produce the best biomass for energy production. They seeded tall and intermediate wheatgrass, Altai and basin wildrye, big bluestem and two switchgrass varieties alone and in combinations in plots at Central Grasslands and the NDSU Research Extension Centers in Hettinger, Minot, Williston and Carrington.

Biomass for energy generally refers to plant material grown for use as biofuel. It also may include biodegradable waste, such as tree limbs and needles, rice hulls and sugar cane fiber.

This 10-year study is a follow-up to one Central Grasslands conducted from 2002 to 2006 in cooperation with the U.S. Department of Agriculture's Agricultural Research Service in Lincoln, Neb., on the feasibility of producing switchgrass as biomass for ethanol.

"That's not to say that switchgrass is the best possible biomass crop for North Dakota, and this research is critical to determine the best options available to our farmers and ranchers as they become involved in producing feedstock for the bioenergy industry," says Ken Grafton, dean of NDSU's College of Agriculture, Food Systems, and Natural Resources and director of the North Dakota Agricultural Experiment Station. "Baseline information provided by this research project will provide our growers with the information necessary to make sound financial decisions."

Researchers learned in the switchgrass study that production varied among the test sites in North Dakota, South Dakota and Nebraska, and the average cost of production was $53 per ton.

"That's pretty high," Central Grasslands director Paul Nyren says of the cost. "For North Dakota farmers to be involved in biomass development for energy, the energy industry has to realize it's not a waste product."

The results of that study started center researchers wondering if other grasses might be more suitable for growing conditions throughout North Dakota and cost less to produce.

"We probably can produce a lot of grasses here very well," Nyren says. "We've raised forages for livestock feed for decades."

But grass for biomass doesn't have to be nutritious or palatable to livestock, he adds. It just needs to convert to energy easily and produce high tonnage per acre.

One issue researchers want to know is how much biomass the various species produce.

"Three to 4 tons per acre would be good," Nyren says. "Forages have normally been harvested for maximum quality in midsummer, rather than for maximum quantity in late summer or early fall."

Other issues the researchers will be studying are:

- The suitability of these perennial forages for biofuels

- The amount of carbon sequestration (storage) in land growing perennial biofuels crops

- The economics of growing perennial forages for energy

- The longevity of the grass species being tested

Nyren thinks this study also could lead to a solution to one of the big concerns among livestock producers – the growing competition from the energy industry for the crops traditionally considered livestock feed.

For example, 17% of the U.S.'s 2006 corn crop was used for ethanol development, NDSU Extension Service beef cattle specialist Greg Lardy estimates. The demand could reach 30% to 35% when the ethanol plants under construction go on line.

Unlike crops such as corn, perennial grasses are suited to growing on highly erodible, fairly marginal land, which would leave cropland available for producing food crops, Nyren says. In addition, perennial grasses provide wildlife habitat.

North Dakota has more than 7 million acres of highly erodible and saline cropland. In some western counties, as much as 90% of the cropland is very erodible.

"Perennial energy crops would achieve more long-term sustainability on these lands by reducing erosion, adding organic matter, reducing greenhouse gases and sequestering carbon," Nyren says.

The researchers plan to harvest their grass plots for the first time in late August or early September.