Production of better quality forage can be achieved by changing grazing method, from continuous grazing by rotational grazing, associated with fertilization practices, especially nitrogen fertilization. It was evaluated during the rainy seasons of 2002/03 and 2003/04 the effect of nitrogen doses (0, 100, 200 and 300 kg ha-1) on dry matter yield and on chemical composition (crude protein, ADF, NDF, hemicellulose, cellulose and lignin) of a Urochroa decumbens cv. Basilisk pasture, managed under rotational grazing. In addition, it was evaluated the efficiencies of two nitrogen sources (ammonium sulfate and urea) and recovery of nitrogen by the pastures. The nitrogen doses, as urea in the first year and ammonium sulfate and urea in the second year, were split in equal applications during the rainy season. Linear effects were found to dry matter (DM) yield and crude protein content in response to the nitrogen applied. Values of 18 and 14 kg DM/kg N applied were obtained in the first and second year, respectively. For crude protein, contents of 9.1 and 11.7% were noted with the application of 300 kg ha-1 N, in the first and second year respectively, whereas in the control treatment (0 kg ha-1 N), the contents found were 6.6% for the first year and 7.1% for the second year. In turn, contents of NDF, ADF, hemicellulose, cellulose and lignin were not affected by nitrogen doses. Sources of urea and ammonium sulfate did not differ from each other. Efficiencies of nitrogen recovery in available dry matter were 33.1, 41.7 and 42.2% in response to 100, 200 and 300 kg ha-1 N, respectively, which can be considered relatively low
dry matter; forage; nitrogen sources; recovery efficiency; Urochroa decumbens
