Do Cover Crops Ameliorate Corn Residue Removal Impacts on Wind Erosion?.

Corn residue removal at high rates is generally known to increase wind erosion potential; however, cover crops (CC) may provide sufficient cover to reduce that potential. What is less understood is how different rates of residue removal and termination date of CC interact to impact wind erosion risks. Our objective was to determine if early- or late-terminated CC can ameliorate effects of different corn residue removal rates (0, 25, 50, 75, and 100%) on wind erosion potential in rainfed and irrigated no-till continuous corn systems after 4 yr of management. We measured dry aggregate-size distribution and computed wind erodible fraction (WEF) in soil samples collected from the 0 to 5 cm depth at early termination and late termination of CC. Soil cover (corn residue plus cover crop) was assessed for each plot using the line-transect method at each sampling date. At the rainfed site, WEF increased with ≥50% residue removal rates relative to no removal. At the irrigated site, WEF increased with ≥75% residue removal rates compared to no removal. At both sites, WEF increased by 17 to 22% with 100% residue removal compared to no removal. There was no significant impact of CC termination date on WEF at either site or sampling time. The WEF and soil cover were correlated by CC termination date at each sampling time where WEF decreased as soil cover increased. Based on our study, it does not appear that CC can ameliorate the increased WEF caused by high rates of residue removal even if they increase soil cover.