1A-07

Impact of Crop Residue Removal on Future Productivity and Soil Quality

Wallace Wilhelm*

USDA-ARS

117 Keim Hall-UNL

Lincoln, Nebraska 68583-0934

Phone:  402)472-1512

Fax:  (402)472-0516

E-mail:  wwilhelm1@unl.edu

Crop residues are viewed as a renewable feedstock for biomass ethanol production that maybe come an additional source of income for crop producers. In addition to the universally accepted roll of crop residues in controlling soil erosion, crop residues are the main source of soil organic carbon (SOC). Many of the characteristics of highly productive soils are attributable to the quantity and quality of SOC. Unfortunately, common crop cultural practices, such as tillage, can accelerate decomposition of SOC, with a concomitant reduction in productivity. If all other factors are constant, SOC is directly related to the amount of residue returned to the soil. To sustainably remove crop residues for use as fuel or chemical feedstock, we must develop systems that conserve soil quality (SOC) and maintain crop and soil productivity. This may be done by removing only the residue that is beyond the amount needed to replenish SOC and use cultural practices that conserve SOC (reduced tillage, cover crops, etc.).