Greenhouse Gas Emission from Corn Rotations and Perennial Grasses in Iowa Grown for Biofuel Production

The ideal bioenergy crop is characterized by high yield, low energy input, low nutrient requirements, low production cost and composition with minimal contaminants. Perennial grasses show better efficiency, higher biomass yield and lower energy input and nutrient requirements than continuous corn or corn-soybean rotations. It is expected that the perennial vegetation has the best efficiency in capturing and storing carbon. In the USA, reed canary grass and switchgrass are considered excellent biofuel crops. Another recently introduced grass is Miscanthus which combines high biomass yield and good combustion qualities. Iowa is currently the US leader in biofuel production. Presently, there have been no comparisons performed on the efficiency of biofuel production between corn rotations vs perennial grasses in Iowa. Evaluation of emissions of greenhouse gases and potential carbon credits is possible by application of the DAYCENT biogeochemistry model.

This work evaluates the magnitude of soil greenhouse gas emissions, fuel production and energy displacement from corn rotations and perennial grasses in Iowa soil and climatic conditions.