Recognizing that growing conditions throughout the Midwest can vary widely, the team performed a county-by-county analysis to gain a high-resolution picture of crop potential rather than generalizing the study across the entire region.
"This research suggests that in order to induce land owners to use their land for bioenergy crops, yield is a critical factor that will influence that decision," Khanna said. "We wanted to look not only at the implication for a representative land owner, but also how it differs across location."
The team began by predicting local yields for the two grass crops. They used an integrated sciences system model, a biophysical model used not only for yields but also estimated carbon uptake and possible atmospheric effects from changes in land use.
"We have to consider the biophysical aspects where the crops can grow in terms of soil, water and nutrient availability, and climate conditions," Jain said.
The researchers found that, in general, the yield is very high for miscanthus up to three times higher than switchgrass in the Midwest. Even through switchgrass is native to the region, it doesn't grow well in higher latitudes like Minnesota or Wisconsin because it has poor tolerance for cold temperatures.
For both grasses, yield varies considerably throughout the Midwest, generally lower in the north and much higher in the south.
Most notably, for the southernmost counties much of southern Illinois and nearly all of Missouri the model predicts greater production of grasses than of current corn and soy crops. This could be a key factor in farmers' decisions to cultivate biofuel crops.
Next, the researchers estimated the minimum price at which landowner would need to sell the two grasses to break even on costs. They conducted a detailed analysis of production over the life of the pl
|Contact: Liz Ahlberg|
University of Illinois at Urbana-Champaign