Hairy vetch （also be called as sand vetch, winter vetch, hairy-pod vetch）is a hardy, viny, annual or biennial legume. Hairy vetch is used as a cover crop, green manure, pasture, and hay. It is capable of accumulating large amounts of dry matter and nitrogen. As a legume, it changes the nitrogen in the air into a form that can be taken up by the squash plants, a process known as nitrogen fixation. The vetch prevents erosion and keeps the ground cooler on hot summer days.
