Tuesday, November 3, 2009: 10:45 AM
Convention Center, Room 317, Third Floor
Planting legumes is a forage management strategy that may offset N fertilization costs and improve stocker cattle gains on pasture. Our objectives were to document herbage availability, average daily gain, and net returns to land, labor, and management from stocker cattle grazing N-fertilized and legume-interseeded bermudagrass pastures. Research was conducted in nine, 1.4-ha paddocks, continuously stocked with 204-kg steers at 2.8 steers/ha, near
, in 2008. Treatments arranged in a completely randomized design included: bermudagrass fertilized with urea at 112 kg N/ha; bermudagrass interseeded with a grazing-type alfalfa at 6.9 kg PLS/ha; and bermudagrass interseeded with a mixture of winter annual legumes (hairy vetch, crimson clover, and arrowleaf clover at 12.3, 9.4, and 5.8 kg PLS/ha, respectively). Legumes were no-till drilled into dormant bermudagrass on 11 Oct. 2007. The N-fertilized system supported 84 grazing days (23 May to 15 August) and gains of 1.12 ± 0.22 kg/d. The alfalfa system supported 56 grazing days (23 May to 18 July) and gains of 1.21 ± 0.23 kg/d. The annual legume system allowed 66 grazing days (24 April to 28 June) and gains of 1.43 ± 0.33 kg/d. Average daily gain and gain/ha were similar among systems (P = 0.65 and 0.13, respectively). Planting annual legumes improved average herbage availability in April and May (2709 ± 223 kg/ha) compared to N-fertilized (1638 ± 134 kg/ha) and alfalfa (1378 ± 184 kg/ha) systems. Average herbage availability in June and July, however, peaked within the N-fertilized system (3683 ± 344 kg/ha) compared to the alfalfa (1339 ± 204 kg/ha) and annual legume systems (1276 ± 180 kg/ha). Net returns were $292, $109, and $227/ha for N-fertilized, alfalfa, and annual legume systems, respectively. Net returns between the N-fertilized and the annual legume system were sensitive to price of N, gain/ha, value of gain, and grazing days. Poor establishment limited herbage availability, grazing days, and net returns within the alfalfa system. The annual legume system has economic potential based on the first year data.