Date of this Version
CROP SCIENCE, VOL. 52, JULY–AUGUST 2012; doi: 10.2135/cropsci2011.08.0455
Grazing warm-season grass pastures with stocker cattle (Bos taurus) is an important economic activity in the southern Great Plains, and substantial increases in the price of N fertilizer have negatively affected profi tability of forage producers. The goal of the study was to determine if bermudagrass [Cynodon dactylon (L.) Pers.] pastures interseeded with either annual or perennial legumes are more profitable than the conventional method of fertilizing with 112 kg N ha–1 commercial fertilizer. A completely randomized design grazing study was conducted in south-central Oklahoma during the spring and summer months of 2008, 2009, and 2010. Preconditioned stocker cattle (260 ± 47 kg head–1) were randomly assigned to pastures (1.42 ± 0.10 ha; three replicates per system) at 2.32 ± 0.40 animals ha–1, beginning when measured standing forage reached 2000 kg ha–1 and grazing continuously until forage mass declined to 1000 kg ha–1. Results of the 3-yr grazing study show that under continuous stocking for the growing conditions common to the south-central Great Plains, the legume systems could not compete economically with the common practice of fertilizing bermudagrass pastures with synthetic inorganic N fertilizer. Results are most sensitive to number of grazing days, price of N, and prices of legume seed.