Produção anual e qualidade de pastagem de Brachiaria decumbens diferida e estratégias de adubação nitrogenada

Annual production and quality of Brachiaria decumbens pastures deferred and strategies nitrogen fertilization. The aim of this work was to evaluate the production of Brachiaria decumbens deferred for periods of 95 and 140 days. Two experimental trials (95 and 140 days) were carried out and, in each one, four fertilization strategies were studied at the beginning and end of summer (0-0, 100-0, 50-50, 0-100 kg ha -1 of N), respectively, with four replications. The highest (p < 0.05) annual production of dry matter (DM) was verified for the fertilization strategy with 100 kg ha -1 of N applied in early summer (100-0), in pastures deferred for 95 days. However, in autumn, winter and spring, the application strategy of 100 kg ha -1 of N at end of summer (0-100) had greater (p < 0.05) forage production. Daily dry matter production, when compared to that of summer, was reduced by 8, 89 and 58% for autumn, winter and spring, respectively, in the 95-day deferring trial. It can be inferred that the strategy of application of 100 kg ha -1 in late summer is an appropriate strategy to increase dry matter production for grasses in the two studied deferral periods, reducing the curve of seasonal annual forage production.