See more from this Session: Cover Crops: Impacts on Agronomic Crops, Soil Productivity, and Environmental Quality: II
A higher N concentration in soil solution from conventional rotation exceeded occasionally the USA drinking water standard of 10 mg L-1, while the sod-based rotation kept it below that level. Nitrogen leaching tended to occur in the wet periods when water fluxes are in line with higher N concentration in the soil solution with N losses up to 22 kg ha-1 from conventional rotation versus 13 kg ha-1 from the same crop sequence of the sod-based rotation. A greater seasonal fluctuation was observed under newly planted bahiagrass with potential load up to 40 kg ha-1. In contrast, less N was leached below the root zone of cotton and peanut from sod-based rotation. The sod-based rotation under conservation tillage improves the use of plant available water by increasing root growth and better utilizing natural resources, which in turn requires fewer external inputs. Compared to conservation-tilled conventional crop rotation, sod-based cropping system can further advance plant growth resulting in higher soil fertility, crop productivity, and environmental sustainability.