Cover crops have been promoted for their abilities to reduce erosion and
retain soil nutrients. Now there is evidence that they can
significantly reduce weed seeds. Crops such as red clover, planted after a main
crop’s harvest, provide cover for insects such as
ground beetles that feed on weed seed. Rodents are also important consumers
of weed seeds and tend to prefer foraging under the
shelter provided by cover. As a result, in fields planted with cover crops,
three to four times more weed seed is eliminated.