A Novel Approach to Grass–Legume Management

Abstract

ABSTRACTSpatially separated monoculture grasses and legumes within the same paddock (SS) may help alleviate constraints to the widespread adoption of legumes in pastures. A grazing study conducted during the winter–spring seasons of 2008 (steers, initial body weight [BW] = 236 ± 24 kg) and 2009 (heifers, initial BW = 245 ± 40 kg) at Raymond, MS, evaluated four forage systems (FS) at two stocking rates (SR; 3 or 6 animals ha−1). Using ‘Marshall’ annual ryegrass (Lolium multiflorum Lam.) and ‘Durana’ white clover (Trifolium repens L.), FS treatments were SS, monoculture grass (MG), monoculture legume (ML), and a binary mixture of grass and legume (MIX). Herbage mass was similar among FS at the high SR (1.9 Mg ha−1), but herbage mass at low SR was greater in MG, MIX, and the grass component of SS than ML and the legume component of SS (2.9 vs. 2.0 Mg ha−1). Among legume plots, SR did not affect herbage mass (1.9 Mg ha−1), but on grass plots, herbage mass was greater at low than high SR (2.9 vs. 2.0 Mg ha−1). Herbage accumulation was greater on grass than on legume plots (32 vs.13 kg ha−1 d−1), but there was no difference among FS within these two forage species. Low SR had greater herbage accumulation (27 kg ha−1 d−1) than high SR (21 kg ha−1 d−1). Average daily gain was greater on SS (1.12 kg) than on ML (0.97 kg), but neither was different from MG (1.08 kg) or MIX (1.00 kg), and greater on low SR than on high SR (1.09 vs. 0.99 kg). These results suggest that a SS system may be an option to enhance adoption of legumes in pastures.