Submitted to: Extension Fact Sheets
Publication Type: Experiment Station
Publication Acceptance Date: 7/20/2005
Publication Date: 8/23/2005
Citation: Singer, J.W., Pedersen, P. 2005. Legume living mulches for corn and soybean. Extension Fact Sheets. Fact Sheet:PM 2006. Available: http://www.extension.iastate.edu/Publications/PM2006.pdf
Technical Abstract: Living mulches are an extension of cover crops used to decrease soil erosion, suppress weeds, improve soil structure and nutrient cycling, and in the case of legumes, supply nitrogen to a grain crop. Unlike cover crops that are killed before planting the grain crop, living mulches co-exist with the crops during the growing season and continue to grow after the crop is harvested. Perennial legumes that could be used for living mulch systems include alfalfa, kura clover, birdsfoot trefoil, white clover, and crownvetch. Competition from the living mulch varies depending on the living mulch species and spring and early summer weather conditions. During a dry spring, living mulches may deplete stored soil water, which may influence early growth of the grain crop. In cool springs, suppression of the living mulch should be applied promptly. There is greater risk of yield loss of the grain crop with early planting dates in Iowa because established living mulches grow rapidly. Seeding rates should be increased by 10 percent because living mulches can interfere with planter operation and seed placement. After planting, mechanical control (rolling, chopping, flaming) in the interrow is necessary for living mulch systems that kill a band rather than using a sublethal broadcast herbicide. The number of mechanical passes depends on timing and weather conditions, which both influence regrowth of the living mulch. The use of shorter season hybrids and varieties should be considered to allow the living mulch more time to recover in the fall. Living mulch systems can provide numerous ecosystem services for corn and soybean farmers, but these systems require diligent management.