Effects of conservation practices on rainfed maize yield, furrow water infiltration, and soil moisture for surface sealing loam soils in the Yazoo-Mississippi Delta

Authors: RIX, JACOB - Pacific Southwest Irrigation; LO, TSZ HIM - Mississippi State University; GHOLSON, DREW - Mississippi State University; SPENCER, DAVE - Mississippi State University; SINGH, GURBIR - University Of Missouri

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/13/2023
Publication Date: 10/25/2023
Citation: Rix, J.P., Lo, T., Gholson, D.M., Spencer, D.G., Singh, G. 2023. Effects of conservation practices on rainfed maize yield, furrow water infiltration, and soil moisture for surface sealing loam soils in the Yazoo-Mississippi Delta. Soil Science Society of America Journal. https://doi.org/10.1002/saj2.20595.
DOI: https://doi.org/10.1002/saj2.20595

Interpretive Summary: Decades of intense tillage across the Mid-South United States and beyond have lead to the problem of surface sealing in loam soils, which restricts infiltration of water into the soils. These soils exhibit low organic matter, poor aggregate stability, and ultimately low infiltration rates. Low infiltration rates decrease rainfed crop productivity and increase irrigation water demand. This research quantified the effects of soil management practices on rainfed maize yield, water infiltration, and soil moisture in Commerce very fine sandy loam and silt loam near Stoneville, MS. The six treatments included cereal rye (CR), furrow diking (FD), no-till (NT), polyacrylamide (PAM), and subsoiling (SS) along with conventional tillage (CT) as a control. No treatment achieved a significantly higher maize grain yield than the CT control treatment in both years consistently. Single-ring infiltrometer results indicated no significant differences among CT, CR, PAM, and SS in 2022 nor between CT and NT in 2021. Neutron probe measurements found that total soil water within the top 1 m was not significantly different among CT, FD, and SS on any of the eight measurement dates throughout the 2022 maize reproductive period. However, soil moisture was numerically lower for FD in the late reproductive stages. These findings suggest that environmental factors and other agronomic operations might counteract some conservation practices, limiting their effectiveness at reducing irrigation requirements to mitigate groundwater depletion in the Mississippi River Valley Alluvial Aquifer. These findings provide additional information for producers and regulatory officials in making conservation decisions.

Technical Abstract: Decades of intense tillage have created the problem of surface sealing in loam soils across the Mid-South United States and beyond. These soils exhibit low organic matter, poor aggregate stability, and ultimately low infiltration rates that decrease rainfed crop productivity and increase irrigation water demand. This research quantified the effects of soil management practices on rainfed maize (Zea mays L.) yield, furrow water infiltration, and soil moisture in Commerce very fine sandy loam and silt loam near Stoneville, MS. The six treatments included conventional tillage (CT), cereal rye (CR; Secale cereale L.), furrow diking (FD), no-till (NT), polyacrylamide (PAM), and subsoiling (SS). No other treatment achieved a significantly higher maize grain yield than the CT control treatment in both years consistently. Single-ring infiltrometer results indicated no significant differences among CT, CR, PAM, and SS in 2022 and between CT and NT in 2021. Neutron attenuation found that total soil water within the top 1 m was not significantly different among CT, FD, and SS on any of the eight measurement dates throughout the 2022 maize reproductive period. However, soil moisture was numerically lower for FD in the late reproductive stages. These findings suggest that environmental factors and other agronomic operations may counteract conservation practices, limiting their effectiveness at reducing irrigation requirements to mitigate groundwater depletion in the Mississippi River Valley Alluvial Aquifer.