A healthy stand of cover crops can out-compete undesirable or noxious weeds for light and nutrients. Some cover crops, like Tillage Radish®, form a dense cover from the dead foliage. This plant is killed by a couple nights with temperatures in the mid-teens. Then the foliage falls to cover the soil such that winter annual weeds never emerge.
This over-winter weed mulching effect is also common with other dense crops, like hairy vetch and winter peas. Tall plants like CCS Winter Triticale shade the soil surface to produce the same effect for limiting weed growth.
Some of the most noxious weeds grow in weak or poor soils. So by building soil health and keeping desirable crops growing year around, undesirable plants can be increasingly crowded out and sometimes eliminated. Cover crops can be a source of root exudates or compounds that provide natural herbicidal effects.
Adds to a Better Bottom Line
Cover crops help build farm profitability through a combination of increased yields and reduced needs for input, including fertilizer, fungicides, insecticides and herbicides.