Crops not typically found in the Midwest -- switchgrass, Indiangrass, big bluestem, eastern gamagrass, sweet sorghum, triticale, kenaf -- are filling several research plots on an Iowa State University farm.
"Our goal is to provide realistic alternatives for producers to diversify their cropping systems," says 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 increasing 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 says.
Ultimately, several projects are underway involving several researchers.
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 to identify ones that yield optimal fiber quality and quantity. Fibers are evaluated for use in bio-composite 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," says Matt Liebman, agronomy professor.
This is the first year for a native perennial grass study 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. Researchers are especially interested in evaluating how nutrients can be recovered from bio-refineries 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," says Liebman.