Bahiagrass Cultivar Response to Grazing Frequency with Limited Nitrogen Fertilization

Warm‐season grasses require N fertilization to achieve their full production potential; however, increased costs have limited the use of N by beef cattle ( Bos spp.) producers. The objective of this study was to test the effects of two grazing frequencies (2 and 4 wk) on production, nutritive value, and persistence of ‘Argentine’ (tetraploid), ‘Pensacola’, ‘Tifton 9’, and ‘UF Riata’ (diploids) bahiagrass ( Paspalum notatum Flügge) cultivars fertilized with 60 kg N ha –1 yr –1 . The study was conducted in Ona, FL, from January 2010 to December 2011. Treatments were eight factorial combinations of two grazing frequencies (2 and 4 wk) and four bahiagrass cultivars. The four cultivars were grazed by beef cows (505±30 kg) for approximately 8 h to a 7.5‐cm stubble height at 2‐ or 4‐wk intervals. Diploid cultivars had greater herbage accumulation (HA) in the spring; however, Argentine had greater annual HA in 2010 and 2011. Plots grazed at 4 wk had approximately 50% greater HA than 2‐wk grazing frequency. Argentine and Pensacola had greater root and rhizome mass than Tifton 9 and UF Riata when grazed every 2 wk, while Argentine had greater cover than any of the diploids when grazed at the 2‐wk frequency. Results show that Argentine is a productive and persistent bahiagrass for beef cattle producers using limited N fertilization and frequent grazing in Florida. Decreasing grazing frequency is an effective management practice to increase bahiagrass HA and persistence, particular the upright‐growing Tifton 9 and UF Riata.