Location: Agricultural Systems ResearchTitle: A meta-analysis on cover crop impact on soil water storage, succeeding crop yield, and water-use efficiency
|WANG, JUN - Northwest University|
|ZHANG, SHAOHONG - Northwest University|
|GHIMIRE, RAJAN - New Mexico State University|
|ZHAO, FAZHU - Northwest University|
Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2021
Publication Date: 7/25/2021
Citation: Wang, J., Zhang, S., Sainju, U.M., Ghimire, R., Zhao, F. 2021. A meta-analysis on cover crop impact on soil water storage, succeeding crop yield, and water-use efficiency. Agricultural Water Management. 256(2021):107085. https://doi.org/10.1016/j.agwat.2021.107085.
Interpretive Summary: Cover crops have many agronomic and environmental benefits, but the effect of cover crop type and management on soil water storage and succeeding crop yields and water use is not clear. Researchers at ARS Sidney, MT in collaboration with Northwest University, Xian, China, in a meta-analysis, found that winter and summer cover crops had variable effect on precipitation-storage efficiency, soil water storage at planting, and succeeding crop yields, evapotranspiration, and water-use efficiency. Improved cover crop management, such as early termination of cover crops, retention of cover crop residue in the soil, and increased years of cover crop plantation enhanced soil water, crop yields, and water-use efficiency. Producers can benefit in crop yields and water-use efficiency by adopting improved cover crop management practices, regardless of cover crop types.
Technical Abstract: Cover crops have many agronomic and environmental benefits for enhancing soil fertility, reducing erosion, and controlling weeds and diseases. However, cover crops may negatively affect succeeding crop yields by consuming soil water, especially in dryland cropping systems. We conducted a meta-analysis on the effect of cover crop type (winter and summer cover crops), biomass yield, and termination date on precipitation storage efficiency (PSE), soil water storage at planting of succeeding crop (SWSp), crop yield, and water use. The PSE maximized at 1.7 Mg ha-1 of cover crop biomass for winter cover crop and at 2.0 Mg ha-1 for summer cover crop compared to no cover crop. The SWSp continued to increase with cover crop biomass of >10 Mg ha-1 for winter cover crop and maximized at 3.8 Mg ha-1 for summer cover crop. While PSE increased with increased years of cover crop growth, SWSp increased with increased interval between cover crop termination and planting of succeeding crop for winter cover crop. The yield of succeeding crop, ET, and WUE varied with cover crop types, biomass yield, residue management, interval between cover crop termination and crop planting, and soil and climatic conditions. Although cover crop type had variable effect on soil water, succeeding crop yield, and WUE compared to no cover crop, early termination of cover crop, retention of crop residue in the soil, and increased years of cover crop growth can enhance these parameters.