Short-Term Effects of Corn Stover Removal for Cellulosic Ethanol Production On Soil Properties: A Regional Assessment.

Corn stover has been identified as a prime feedstock for large-scale cellulosic ethanol production. Recent climate change legislation in the U.S. has created an incentive for the agricultural sector to provide bio-energy feedstock. Therefore, understanding the impacts of widespread stover harvest on soil and environment is essential to establish soil-specific stover harvest rates. We assessed the effects of variable levels of corn stover removal on soil properties on a regional scale across three contrasting locations (Colby, Hugoton, and Ottawa) in Kansas. Five stover treatments that consisted of removing 0, 25, 50, 75, and 100% of corn stover after harvest were studied for changes in bulk density, aggregate stability, soil organic C (SOC), soil water content, soil temperature, and water retention over time. Bulk density, aggregate stability, and water content were measured periodically, while soil water content and temperature were collected continuously throughout the experiment using automated sensors. Results of this regional study showed that soil bulk density decreased with decrease in stover removal at all locations. In contrast, aggregate stability and soil water content increased with decrease in stover removal rate at all sites. Soil temperature tended to fluctuate much more heavily in plots with high amounts of stover removal, compared to low removal rates. Our results from the first year of stover management suggest that high rates of stover removal for cellulosic ethanol production will increase bulk density and decrease soil water content, and aggregate stability. These short-term changes in soil properties may result in decreased agricultural productivity.