Iowa State Scientists Study Alternative Crops for Fuel Production

August 24th, 2006

AMES, Iowa — Crops not routinely found on Iowa farms — switchgrass, Indiangrass, big bluestem, eastern gamagrass, sweet sorghum, triticale, kenaf — fill several research plots on an Iowa State University farm west of Ames.

"Our primary goal is to provide realistic alternatives for Iowa producers to diversify their cropping systems," said Ken Moore, agronomy professor. But he's quick to point out this isn't just about developing alternative crops, but also developing uses for the new crops. For instance, emerging markets for liquid fuels and other industrial products made from crop biomass offer opportunities.

"This requires development of an industrial market for these alternative biomass crops. In the end, the research should benefit not just producers, but also consumers and the alternative fuels industry," he said.

Several projects are underway. Others involved with Moore in the research are Matt Liebman, agronomy professor, and Robert Anex, associate professor of agricultural and biosystems engineering.

This is the third year for a pair of projects evaluating kenaf varieties and production practices for Iowa, funded by the Department of Agronomy Endowment. The crop usually is grown for industrial fiber, but also is a potential biomass crop.

Several varieties of kenaf have been planted with the goal of identifying ones that yield optimal fiber quality and quantity. The fibers are evaluated for use in biocomposite materials and ethanol production. This research also involves studying the best management practices for growing kenaf in Iowa and an economic evaluation of the industrial use of kenaf and its by-products.

It's the second year for a project involving five sweet sorghum varieties and management practices, funded by the Iowa Energy Center. Once harvested, each variety is evaluated to determine how well it is suited for ethanol production.

A concern sometimes raised about the use of annual crops for biomass is that removing large amounts of crop residue from fields might lead to greater soil erosion, reduced soil fertility and increased need for commercial fertilizers.

"To address these challenges, we are investigating two types of alternative cropping systems and associated management practices that might be used to generate large amounts of biomass feedstocks while better protecting environmental quality," said Liebman.

This is the first year for a study of native perennial grasses that show promise for biomass production - switchgrass, Indiangrass, big bluestem and eastern gamagrass. Various management practices are being evaluated and samples collected to compare biomass production, carbon storage and nutrient use efficiency. Liebman, Anex, Moore and graduate student Andrew Heggenstaller are especially interested in evaluating how nutrients can be recovered from biorefineries as grass biomass is processed, and how those nutrients can be recycled to the fields where the perennial grasses grew.

This also is the first year of a long-term crop rotation study that looks at the possibility of a double-crop sequence of winter and summer biomass crops. Triticale, a cross between wheat and rye, is planted in October and harvested for biomass the following June. Then warm-season crops such as corn, sorghum-sudangrass and crotalaria, a legume that can fix large quantities of atmospheric nitrogen, are planted.

"Our theory is that producing two crops in one year will generate more biomass at lower environmental cost than will a single crop of corn," Liebman said.

Liebman has set up his work with funding from the Ecology Initiative of the Leopold Center for Sustainable Agriculture, Iowa State's Plant Sciences Institute and the Center for Global and Regional Environmental Research at the University of Iowa.

The potential for new biomass crops is being highlighted during the 2006 Biobased Industry Outlook Conference: Growing the Bioeconomy Aug. 28-29 at Iowa State University's Scheman Center. A tour of the research plots where these potential new biomass crops are being grown will take place on Aug. 29. The tour begins with researcher presentations at 8:30 a.m. at Scheman. Participants then will board a bus to be transported to the field plots.


Ken Moore, Agronomy, (515) 294-5482,
Matt Liebman, Agronomy, (515) 294-7486,
Susan Thompson, Communications Service, (515) 294-0705,
Research plot photos available on request from Susan Thompson.