Leopold Center for Sustainable Agriculture

Landscape Biomass project seeks biofuel options

Back to Leopold Letter Winter 2012

The Leopold Center has developed a new brochure about the Landscape Biomass project, which is in its fourth year of a planned 10-year study. The experiment at ISU’s Uthe Farm compares replicated plots of five potential biofuel feedstock cropping systems: continuous corn and four alternatives that include soybean, triticale, switchgrass, sorghum or aspen trees. The cropping systems are planted at five different positions on the landscape, from the summit of the hill to the floodplain.

Corn has been the highest yielding crop in the first three years of the experiment. Researchers expect corn yields to stabilize or decrease slightly over time and perennial crop yields to increase as they mature. At present, none of the alternative systems are economically competitive with corn.

Yet the experiment shows that continuous corn has serious environmental impacts, particularly to water quality, a growing concern in Iowa. Samples of soil moisture drawn from the corn plots have contained the highest levels of nitrogen compared to the other systems. In contrast, the aspen tree system, intercropped with triticale, had almost no nitrogen in its soil moisture.

Alternative systems also seem to create healthier soils by building organic matter and recycling nutrients. Early research indicates they may have lower greenhouse gas emissions as well.

Back to Leopold Letter Winter 2012