Wheat Cover Crop Effects on Water and Physical Conditions of Piedmont Soil.

Effectively managing a cover crop along with a cash crop requires proper knowledge of associated changes to soil conditions such as water availability and residue cover during planting of the cash crop. We modified a long-term agronomic trial in the piedmont region of North Carolina to include a winter wheat cover crop within a corn and soybean rotation. The trial compared tillage with or without a cover crop and included no-till, disc, chisel, and moldboard tillage in 2016 and 2017. Wheat was planted after harvest, and terminated before planting the cash crop. Soil water content and bulk density were measured to 15 cm depth, above ground cover crop biomass was measured in mid-April, and crops were harvested with a combine. Cover crop biomass was from 6559-8308 kg ha^-1 for treatments in 2016 and declined to 2952-3626 kg ha^-1 in 2017, likely because of late cover crop planting in 2017. Soil water content ranged from 20.3-25.0% and was similar among treatments for both years, regardless of cover cropping or tillage. Soil bulk density was also not different among the treatments. Average soybean yield in 2016 was greatest from cover cropped, chisel plowed soil (2355 kg ha-1) and least from moldboard plowing with no cover. The 2017 harvest is still pending. Potential changes to soil physical conditions associated with cover cropping were not apparent in this short-term study. After planting the cover crop, water availability and crop yield remained sufficient for this corn-soybean rotation in piedmont soil, which means that cover cropping can work in this region. The next focus of the study is to measure aggregate stability and water infiltration rates in the same trial.