Managing Winter Cover Crops in Cotton to Improve Soil Health

University of Missouri Delta Center research has shown significant cotton yield increases from planting wheat cover crops in the row middles for wind protection. The Natural Resource Conservation Service is promoting soil quality programs with mixtures of cover crops which would be grown year round. These mixtures can help to diversify the soil ecology in addition to maintaining some type of live root growing in the soil at all times. This will allow for uninterrupted, favorable conditions for soil organisms, including possible fungi parasitic to nematodes. Cover crop residue may also leave concentrated areas of available soil phosphorus. The polysaccharide mucous secretions from the soil organisms increase soil aggregate stability, promote good aeration, and water infiltration and retention.

The objective of this experiment is to evaluate the effect of cover crops on soil physical and chemical properties. This will help us to determine which cover crops and cover crop mixtures improve cotton growth and yields while enhancing soil health.

Cover crops were seeded in the fall of 2012 just after the cotton harvest on two locations. Cover crop treatments included wheat, cereal rye, Austrian winter peas, crimson clover, tillage radish, and rapeseed as well as two cover crop mixtures (Peas/Rye/Radish and Clover/Wheat/Rapeseed). These cover crops were allowed to grow through the winter and were terminated shortly after cotton planting. Bulk density, soil respiration, and water infiltration were all measured during the season, and cotton lint yield was taken at harvest.