Índice de área foliar, densidade de perfilhos e acúmulo de forragem em pastagem de capim-braquiária adubada com nitrogênio

This experiment was carried out in the agrostology sector of the UFV Animal Sciences Department, from November 2001 to November 2002. The objective was to evaluate the effects of nitrogen fertilization on sward leaf area index, tiller population density and herbage accumulation of Brachiaria decumbens Stapf. pastures fertilized with nitrogen and subjected to a common grazing height. Treatments consisted of four nitrogen doses (75, 150, 225 and 300 kg.ha-1.yr-1. N) applied prior to the beginning of the evaluations, which were performed during the Summer, Autumn, Winter and Spring in 2002. The experimental design used was a complete randomized block with two replications. There was a linear increase in leaf area index and tiller population density with increasing nitrogen doses. Herbage dry matter accumulation was also increased by nitrogen application, with higher daily accumulation rates registered during Summer-Spring and lower rates during Winter. Sward leaf area index, tiller population density and herbage accumulation varied with season of the year, with lowest values being consistently recorded during Winter.