A Novel Approach to Legume Management.

            Grazing systems consisting of spatially separated monoculture grasses and legumes within the same paddock (SS) may help alleviate constraints with the yet elusive widespread adoption of utilizing legumes in pastures.  A grazing study conducted during the winter-spring season of 2008 (using steers, initial BW = 236 kg) and 2009 (using heifers, initial BW = 245 kg) at Raymond, MS quantified pasture and animal responses of four forage systems (FS) grazed 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 included SS, monoculture grass (MG), monoculture legume (ML), and a binary mixture of grass and legume (MIX).  Responses were considered different at P < 0.05.  Averaged across years, herbage mass (HM) was similar among FS at the high SR (1.9 Mg ha^‑1), but at low SR, plots with grass (MG, MIX, and the grass component of SS) had greater HM (2.9 vs. 2.0 Mg ha^‑1) than plots of legume monocultures (ML and the legume component of SS).  Among legume monocultures, SR did not affect HM (1.9 Mg ha^‑1), but on plots with grass, HM was greater on low compared to high SR (2.9 vs. 2.0 Mg ha^‑1). Crop growth rate (CGR) on plots with grass was greater than that of legume monocultures (32 vs.13 kg ha^‑1 d^‑1), but there was no difference among FS within these two sets of treatments.  Low SR had greater CGR (27 kg ha^‑1 d^‑1) than high SR (21 kg ha^‑1 d^‑1).  Animals on SS (1.12 kg) had greater average daily gain (ADG) than ML (0.97 kg), but neither was different from MG (1.08 kg) or MIX (1.00 kg).  Animals on low SR had greater ADG than high SR (1.09 vs. 0.99 kg).  Across FS, high SR had greater liveweight gain ha^‑1 (LWG) than low SR.  At high SR, SS had greater LWG (888 kg ha^‑1) than the other FS (mean = 655 kg ha^‑1) while at low SR, the LWG on SS, MG and MIX was similar (mean = 458 kg ha^‑1) but greater than LWG on ML (340 kg ha^-1).  At high SR, forage allowance (FA; kg DM kg^‑1 LW) was not different among FS (1.1), but compared to high SR, FA was greater at low SR and different among FS, ranking MG (3.4) > MIX (3.0) > SS (2.5) > ML (2.2). These results indicate that a grazing system with spatially separated monoculture grasses and legumes within the same paddock has potential to improve pasture productivity.