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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Production Systems Research » Research » Publications at this Location » Publication #376581
Research Project: Assessment and Improvement of Soil Health under Modern Cropping Systems in the Mid-Southern United States

Location: Crop Production Systems Research

Title: Soil water dynamics under a warm-season cover crop mixture in continuous wheat

Author
item Mubvumba, Partson
item DELAUNE, PAUL - Texas A&M Agrilife
item HONS, FRANK - Texas A&M University

Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2020
Publication Date: 10/23/2020
Citation: Mubvumba, P., Delaune, P.B., Hons, F.M. 2020. Soil water dynamics under a warm-season cover crop mixture in continuous wheat. Soil and Tillage Research. p.104823. https://doi.org/10.1016/j.still.2020.104823.
DOI: https://doi.org/10.1016/j.still.2020.104823

Interpretive Summary: Cover crop (CC) use can potentially benefit monoculture wheat systems in the semi-arid US Southern Great Plains, but the biggest hurdle in such regions where evapotranspiration exceeds precipitation is soil water. CC impact on soil water use and availability is a major cause for concern in water-limited environments. Scientists at the Texas A&M University and USDA Crop Production Systems Research Unit in Stoneville conducted a study to evaluate the impact of CC, grazing, and intercrops on soil water changes under rainfed conditions in the Texas Rolling Plains. CC mixture produced 1910 to 3125 lbs/ac dry herbage mass. Stored soil water was 22 to 26% lower in CC plots at time of termination. Stored soil water increased two to four times for CC compared to non-CC treatments between CC termination and wheat planting. These results demonstrated that greater infiltration and water capture after termination of CC has the potential to make up for the loss in soil water that CC had utilized.

Technical Abstract: Cover crop technology can potentially benefit monoculture wheat systems in the semi-arid US Southern Great Plains, but the biggest hurdle in such regions where evapotranspiration exceeds precipitation is soil water. Cover crop impact on soil water use and availability is a major cause for concern in water-limited environments. The objective of this study was to evaluate the impact of cover crops, grazing, and intercrops on soil water dynamics under rainfed conditions. Seven treatments were evaluated, including conventional tillage (CT) and combinations of no-tillage (NT) with a cover crop mixture, grazed cover crops, and/or cash crop intercropping. The three-year study was conducted on a long-term NT continuous wheat system in the Texas Rolling Plains. Despite drier periods, the cover crop mixture produced 2141 to 3503 kg ha-1 dry herbage mass. Stored soil water was significantly lower within 60 days after planting for cover crop compared to no cover crop treatments. Stored soil water was 22 to 26% lower in cover crop plots at time of termination. In the final two years of the study, the positive change in stored soil water from cover crop termination to wheat planting was two to four times greater for cover crop treatments compared to non-cover crop treatments. The greater infiltration and water capture after termination has the potential to make up for the loss in soil water that cover crops used.