Varietal Differences In Hairy Vetch Growth Rate, Nitrogen Content, and Fixation.

Legume cover crops play an important role in providing sustainable forms of nitrogen for crop production. While there have been considerable efforts to characterize a range of legume species and their nitrogen accumulation, few studies have quantified varietal differences in legume cover crop growth rates, nitrogen content, and fixation. We conducted field studies on six hairy vetch accessions, over a four-year period, that quantified biomass, nitrogen content and fixation at five intervals from spring green-up to 50% flowering. Hairy vetch growth stage was documented at each destructive harvest to determine variations in maturation between accessions. Hairy vetch varieties were selected based on availability and to reflect a range of maturation timing and winter hardiness. Winter hardiness and early flowering timing appear to be negatively correlated. Early flowering varieties had faster growth rates and typically produced comparable biomass to late maturing varieties. This work will allow growers to make regionally specific selections of hairy vetch when used as a cover crop.