White Clover Effect On Improving Tall Fescue Pastures.

White clover (Trifolium repens L.) overseeded in deteriorating tall fescue [Lolium arundinaceum (Schreb.) Darbysh.], formerly Festuca arundinacea (Schreb.) pastures may improve pasture quality, reduce N fertilizer use, and may even halt decreasing tall fescue stand density.  This study evaluated pasture and animal responses of poor stand density, novel endophyte tall fescue pastures overseeded with either ‘Durana' white clover (DWC) or an experimental white clover cultivar from the Noble Foundation, NFWC04-49 (NWC), and a non-overseeded control (TF).  Overseeded treatments were replicated twice and the control was replicated four times using a randomized complete block design.  Each paddock (0.8 ha) was grazed by two Angus crossbred steers (initial BW = 286 kg) for 56 d from mid April to mid June, 2010.  Responses were considered different at P < 0.05.  Visual estimates determined that tall fescue composition was 56% in TF, 29% in NWC, and 18% in DWC swards.  White clover composition was greater in DWC than NWC (44 vs. 31%) but swards of all three forage systems had about the same proportion of weeds (≈ 40%; mainly little barley [Hordeum pusillum Nutt.], bahiagrass [Paspalum notatum Flϋgge], and bermudagrass [Cynodon dactylon (L.) Pers.]) to desired species. Average daily gain was not different between overseeded treatments (0.89 kg, Durana; 0.76 kg, NFWC04-49) but both were greater than the control (0.59 kg).  Average herbage mass was similar across treatments (1040 – 1140 kg ha^‑1), but herbage accumulation was greater for overseeded pastures (average = 17.5 kg ha^‑1 d^‑1) than the control (8.5 kg ha^‑1 d^‑1).  This led to greater herbage disappearance (15.5 vs. 5.9 kg ha^‑1 d^‑1), indicating potentially more forage intake on the overseeded treatments.  These preliminary results demonstrate that pasture quality, indicated by animal performance, and pasture growth rate were improved by overseeding deteriorating tall fescue pastures with white clover.