Aerial Interseeded Cover Crop and Corn Residue Harvest: Soil and Crop Impacts

Corn (Zea mays L.) residue is a forage source and a biofuel feedstock. Excessive residue harvest may, however, result in increased soil erosion risks and degraded soil properties. Aerial interseeding of a cover crop (CC) before harvesting corn may off set adverse effects of residue harvest. We studied the impacts of harvesting 71% of corn residue with and without aerially interseeded winter rye (Secale cereale L.) CC on wind and water erosion potential, soil organic carbon (SOC), nutrients, soil water content, and corn yields in a farmer's field under irrigated strip till continuous corn on a sandy loam in the western Corn Belt from 2013 to 2016. Interseeded CC biomass yield ranged from 0.2 to 3.4 Mg ha(-1). Corn residue harvest reduced geometric mean diameter of dry soil aggregates and increased wind erodible fraction (< 0.84 mm aggregates) by 0, 27, and 37% in the fi rst, second, and third year, respectively, indicating that residue harvest increased the soil's susceptibility to wind erosion. Cover crop had no effect on geometric mean diameter and erodible fraction. Residue harvest reduced near-surface water content but CC had no effect. Treatments did not affect fertility properties and corn yield. In spring, surface cover was 24.7% in residue-harvested plots without CC and 65.3% in residueharvested plots with CC, indicating that CC provided soil protective cover. Overall. interseeded grass CC may not rapidly improve soil properties, but the added soil cover provided by the interseeded CC could partly off set the eff ect of residue harvest on wind erosion potential in sandy loam soils.