Soil Conservation As Affected By Cover Cropping Practices and Species in Corn-Soybean Rotations.

The Revised Universal Soil Loss Equation 2 (RUSLE2) is a tool for modeling soil erosion and sediment delivery in response to environmental factors and cropping practices. Modeling the loss and gain of soil, as affected by agronomic management, provides information to assess the sustainability of varying cropping practices. This research used RUSLE2 to predict the amount of soil loss mitigated by cover crops. One project in Waseca and Lamberton, MN (2014, 2015, and 2016) established 5 different cover crop options in standing corn at growth stage V7. Cover crops were terminated with glyphosate in the spring, and soybeans were no-till planted into the residues. In a separate relay cropping project in Morris and Lamberton, MN (2015 and 2016) winter oilseed cover crops were interseeded into corn at R6 followed by relay planting soybeans into the living oilseed crop to allow for oilseed harvest. Cover crop biomass data from all experiments were included with cropping practices, as well as soil and environmental factors in RUSLE2 to estimate soil savings associated with cover crop type and residue accumulation across varying conditions and systems. Additionally, biomass measurements were applied to RUSLE2 to manipulate cofactors of soil erodibility, slope length, and slope steepness to simulate soil conservation of cover crops in highly erodible field situations.