Interseeding Novel Cool‐Season Annual Legumes to Improve Bermudagrass Paddocks

Abstract

ABSTRACTInterseeding nontraditional, cool‐season legumes into bermudagrass [Cynodon dactylon (L.) Pers.] paddocks was evaluated as an approach to increasing the quality and duration of forage production and replacing a portion of the N fertilizer required in the southern Great Plains. We compared the effects of interseeding either grass pea (Lathyrus sativa L. ‘AC‐Greenfix’) or lentil (Lens culinaris Med. ‘Indianhead’) with N fertilizer rates of 0, 45, or 90 kg ha−1 N. All plots received 60 kg P205 ha−1 in early March. The legume and fertilizer treatments were imposed in mid‐March during 2001, 2002, and 2003. Forage samples were clipped from 0.25 m−2 quadrats on five sampling dates between 1 May and 15 July each year. Yield, N concentration, species composition, and in vitro digestible dry matter (IVDDM) were determined. Year, sampling date, and treatment showed significant (P < 0.05) effects, as did the two‐way interactions between all three factors. Total end‐of‐season standing dry matter of bermudagrass and grass pea was 5550 ± 423 (SEM) kg ha−1, which was similar to biomass production with 45 kg ha−1 N (5305 ± 570 kg ha−1) and less than that produced with 90 kg ha−1 N (7785 ± 725 kg ha−1). Forage N and IVDDM concentrations for the grass pea treatment were 34 and 6% higher than for bermudagrass, but N and IVDDM concentrations of the forage mixture were intermediate between the higher N rates. Although additional studies are needed to optimize management for the interseeded legumes, we conclude that this practice can improve the quality and duration of bermudagrass forage production in this region.