Leopold Center - Project studies next generation of biorenewables

The Leopold Center’s Ecology Initiative is supporting an Iowa State University research project poised to play an important part in developing the next generation of biorenewables. These products will use a wide range of crops in addition to corn to produce cellulosic feedstocks.

The project looks at double cropping systems and alternative crops to produce biomass feedstock more efficiently and with more beneficial effects on the environment than conventional corn-soybean or continuous corn systems. When combined with advanced biomass conversion technologies, the new systems could offer great promise, says Matt Liebman, a professor of agronomy and a lead investigator for the project.

“We’re at a very important point in Iowa’s agricultural history,” Liebman said at a November 7 biorenewables town meeting hosted by the ISU College of Agriculture.

“The conversion of biomass into ethanol presents important opportunities to increase the volume of biofuels produced and increase the energetic efficiency of doing that, while improving protection of soil and water resources,” he added.

Also involved in the project are Robert Anex, associate professor of Agricultural and Biosystems Engineering; Ken Moore, professor of agronomy; and Andrew Heggenstaller, a Ph.D. student in agronomy and biorenewable resources and technology. The project also was highlighted during the Biobased Industry Outlook Conference at ISU in August.

One of the cropping systems involves planting the cool-season crop, triticale (a highly productive cross of rye and wheat), followed by a warm-season crop of corn, sorghum-sudangrass or crotalaria (a subtropical legume). Preliminary results from the first growing season show production of 9 to 10 tons of biomass per acre, compared to 7.4 tons biomass/acre under the conventional corn system.

“Triticale looks like a superior plant to work with in terms of producing winter cover, preventing nutrient loss and producing a large amount of harvestable biomass,” Liebman said. (The Leopold Center has been a major supporter of the triticale research at ISU.)

The team also is studying how to use native perennial grasses such as switchgrass, Indiangrass, big bluestem and eastern gamagrass for biomass production. Various management practices are being evaluated and samples collected to compare biomass production, carbon storage and nutrient use efficiency. Investigators also are 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.

Liebman said the perennials are important because of their inherent advantages over annual crops.

“Perennials build and conserve soil, capture and store carbon, hold and filter water very effectively and they provide some wildlife habitat,” he said. “They also are very good at cycling nutrients.”

The project is supported by a special two-year grant from the Center’s Ecology Initiative, with funds from the National Science Foundation, ISU Plant Sciences Institute, University of Iowa Center for Global and Regional Environmental Research, Monsanto, and the ISU departments of Agronomy and Agricultural and Biosystems Engineering.