Changes in Soil Water Dynamics Under Diverse and High Residue Cover Crops.

Sandy loam soils of the Eastern Shore are very low in organic matter as a result of decades of intensive farming, which can lead to increased nitrogen leaching and lower yields.  Diverse cover crop mixtures, made up of three or more cover crops, and no-till can be used to improve soil quality and crop yields.  A three-year experiment with diverse cover crop mixtures added to no-till corn and soybean rotations was established in 2014 to quantify to soil quality improvements of cover crops used in rotation.  There are twelve cover crop treatments, comparing both individual and diverse cover crop mixtures and summer and winter cover crop to traditional corn, soybeans and wheat rotation.  Cover crops can improve soil water management by increasing infiltration, reducing runoff by covering the soil surface, and the cover crop residues act like a mulch to conserve moisture during the summer months for the cash crop.  However, there are concerns about cover crops keeping the soil cooler and wetter in the spring and delaying planting and growth or depleting moisture from the soil before the cash crop, especially with high biomass producing cover crops.  To better understand how cover crops influence soil water dynamics in a sandy soil in a subtropical climate volumetric soil moisture sensors measure soil moisture at 6, 12, 18 and 24 inches, both above and below a hardpan.  Bulk density, soil compaction and infiltration were also measured to understand how changes in soil quality affect soil water movement.