Nutrient Profiling and Water Repellency of Cover Crop Residues in Southern United States Agroecosystems

Integrating cover crops (CCs) into crop rotations has gained interest in the Southeastern United States due to the benefits that CCs offer, which improve soil health for agricultural production. However, more information is needed on how CCs may affect the development of soil water repellency (SWR), which can negatively impact soil hydrology. The development of SWR threatens crop yields, food security, and farmer livelihoods. To address this knowledge gap, a field experiment measured the water repellency (WR) of four common CC species and a fallow treatment. CC samples were oven-dried, ground, and analyzed for WR using the water drop penetration time (WDPT) test. The mean WDPTs of the CC residues collected at termination and four weeks post-termination ranged from 49 to 4174 and 8 to 2627 s, respectively. Large WDPTs (>5 s) indicate that CC residues can potentially influence the development of SWR. All CC residues exhibited WR. The results suggest that farmers may need to consider alternative CC species depending on when they plant their cash crops in relation to CC termination. Considering the effects of CCs on SWR will enable farmers to make informed management decisions to mitigate SWR development and maintain soil health in a changing climate.