Proceedings of the 2022 Mississippi Water Resources Conference

Year: 2022 Authors: Roberts C., Gholson D., Locke M., Spencer D., Steinriede R.W., Krutz L.J., Pieralisi B., Crow W.

Conservation cropping systems have many benefits; most of these are associated with water use, infiltration, and water runoff quality. Despite these potential benefits, research and development of effective conservation cropping methods for cotton producers in the Mid-South are limited. A study is being conducted in Stoneville, MS, from 2021 to 2023 to determine how cotton yield, water use efficiency (WUE), and nutrient and soil in water runoff are influenced by conservation tillage and cover cropping systems. Study treatments were established in the fall of 2020 and included reduced tillage, subsoil, winter fallow (RT), strip till, winter fallow (ST), strip till, cover crop (ST, CC), strip till, subsoil, cover crop (ST, SS, CC), no till, winter fallow (NT), no till, cover crop (NT, CC), no till, and minimal surface disturbance subsoil, cover crop (NT, SS, CC) In the first year of full study implementation (2021), lint yield was decreased in no-till (NT) treatments by up to 16% (1382 kg ha^-1) compared to conventional reduced tillage (RT; 1647 kg ha^-1). Strip-tillage coupled with cover crops did not have an impact on yield compared to RT. Tailwater runoff from a rainfall event in late August did not differ between treatments. Preliminary observations indicate that glyphosate concentration in runoff water is greater following a burndown application of glyphosate in NT,CC and NT,SS,CC treatments (907 μg L^-1) than in RT treatments (482 μg L^-1). Few conclusions can be made regarding irrigation WUE since irrigation only occurred in a single RT plot due to exceptional rainfall. Since this is the first complete year of treatment implementation, treatment effects are expected to become more apparent as this long-term study continues.