This experimentwas carried out to evaluate the effects of nitrogen fertilization upon the morphogeneticaland structural characteristics of Brachiaria decumbens under grazing.Four nitrogen rates (75, 150, 225 and 300 kg/ha.yr) were applied before thebeginning of the experimental evaluations, which were performed during the Summer,Fall, Winter and Spring seasons. The randomized complete block design was usedwith two replications. Linear increases were observed for the leaf elongationrate, final leaf length, leaf area index, stem and leaf blade percentage. Thepercentage of dead material decreased with the nitrogen fertilization. On theother hand, N fertilization had no effect on the number of alive leaf, numberof emerging leaves, total numbers of leaves, stem elongation rate and senescencerate. Leaf and stem elongation rates, number of alive leaf, final leaf length,leaf area index, leaf blade and stem percentages in the Brachiaria decumbensvaried among seasons, lower values occurring in the winter.
