Cassandra Schnarr, Department of Soil and Crop Sciences, Colorado State University, Loveland, CO, Meagan E. Schipanski, Colorado State University, Fort Collins, CO and John Tatarko, USDA-ARS, Manhattan, KS
Wind erosion of soil is a destructive process impacting crop productivity and human health and safety. The mechanics of wind erosion and soil properties that influence erosion are well understood. Less well-studied are the effects that cropping intensity has upon those soil properties. We collected soil samples from a cropping systems experiment maintained since 1985 at 3 locations across eastern Colorado that represent a climate gradient. We measured the long-term effects of three no-till crop rotation systems of differing intensities (wheat-fallow, wheat-corn-fallow, continuous cropping) on soil carbon and soil aggregate strength. Samples to a depth of 2.5 cm were collected in May 2015. Soil aggregates were crushed using a Soil Aggregate Crushing Energy Meter (SACEM) and analyzed for total organic carbon content. Location had a significant effect on aggregation and soil carbon, but rotation systems did not differ in aggregation strength. We are also quantifying changes in residue cover across the rotation systems, which is another factor in reducing wind erosion susceptibility. While the choice of increased cropping system intensity has many benefits to producers, it may not improve soil properties sufficiently to improve resistance to wind erodibility. Future directions with this research include investigating the underlying mechanisms for the carbon and aggregation by analyzing the microbial communities in the systems.