The effect of residual nitrogen fertilization on the yield components, forage quality, and performance of beef cattle fed on Mombaca grass

The objective of this study was to evaluate the effect of residual nitrogen (N) on pastures of Mombaca grass and its impact on pasture structure and the nutritive value and performance of beef cattle. The experiment analyzed randomized blocks subdivided into plots, with three replications. The research focused on a number of pastures having received three annual doses of N (100, 200 and 300 kg ha(-1)) from 2015 to 2017, with no N fertilization in 2018. The results indicated that pastures under residual effect of 300 kg ha(-1) of N were characterized by higher (P<0.05) rates of forage accumulation than those under the residual effect of 100 kg ha(-1) N. Furthermore, this study indicated no effect (P>0.05) on the pasture nutritive value and average daily gain (0.490 kg day(-1)). The stocking rate was higher (P<0.05) in pastures under the residual effect of 300 kg ha(-1) of N, and lower in those at 100 kg ha(-1) of N, while weight gain per area followed the trend observed in the stocking rate. The results thus suggest that the suspension of N fertilization for one year after three years of sequential fertilization was responsible for an immediate loss of 50 and 55% of the productivity of plants and animals, respectively.