Contribution of Field Pea to Winter Forage Production and Nutritive Value in the South‐Central United States

Abstract

Field pea [Pisum sativum L. subsp. sativum var. arvense (L.) Poir] appears to hold promise as a cool‐season legume option for the south‐central United States. A 2‐yr field study at two locations in Louisiana was conducted to evaluate forage dry matter (DM) production and nutritive value of an oat (Avena sativa L.)–field pea combination and an annual ryegrass (Lolium multiflorum L.)–field pea combination at different field pea seeding rates. Monocultures of the grasses at a range of N fertilizer rates were included for comparison. Increasing seeding rates of field pea increased forage DM production linearly (P < 0.05) and linearly (P < 0.01) increased crude protein from forage of interseeded plantings. Interseeding field pea did not improve in vitro true digestibility of oat–field pea or annual ryegrass–field pea forage at either harvest, even though the annual grasses maintained a similar high digestibility to field pea only at the first harvest. Nitrogen fertilizer, which produced a linear increase in forage production with increasing N rate, provides more flexibility and easier management than the use of legumes. Cost of N will determine when the use of legumes such as field pea is a preferred option. The improved forage nutritive value of interseeded field pea can be a meaningful benefit with specific classes of livestock and production goals.