Can Living Mulches Reduce Weed Seed Banks in Fresh Market Tomatoes?

Weeds that emerge late in the growing season can escape control and contribute to large increases in the soil weed seed bank.   This is particularly problematic in widely spaced row crops like tomatoes where weeds that emerge between rows face no competition from the crop.  In a series of experiments, we planted buckwheat and red or crimson clover between rows six to eight weeks after transplanting tomatoes. The living mulches were mowed to limit competition with the crop and, in the case of buckwheat, to prevent seed production by the mulch.   Both living mulches reduced weed seed production and either reduced weed seed banks or weed emergence in the following year. Tomato yields were not affected by buckwheat but were reduced by the use of clover as a living mulch.  Potential explanations for these results and suggestions for using living mulches will be discussed.