N-fixing legume and green manure
Vicia sativa has a high ability to fix nitrogen provided that the seeds are inoculated with an adequate rhizobium strain or that it has been sown previously on the field (FAO, 2010; Sattell et al., 1998). It can provide N either to the cereal companion crop when sown in mixed pastures, or to the following crop when sown alone.
Crop residues are succulent and decompose quickly, and are an appreciated green manure. The best stage is full bloom: Vicia sativa residues are easily ploughed down with a disc harrow (UC SAREP, 2006). They provide a moisture-conserving mulch in strip-tillage systems. Thanks to N fixation, common vetch lowers the overall C:N ratio of mixed pastures (common vetch/cereal), and speeds up decomposition (Sattell et al., 1998).
Cover crop
Common vetch helps with the suppression of spring weeds and is a valuable cover crop in vineyards and orchards (Sattell et al., 1998). Weed suppression is increased when the legume is associated with a cereal companion crop (UC SAREP, 2006).