Biomass components and structure of massai grass fertilized with nitrogen and grazed by sheep

To evaluate the biomass components of massai grass subjected to nitrogen (N) fertilization levels (control - 0; 400; 800 and 1200 kg ha(-1) year(-1) of N) and under rotational stocking with sheep, this study was undertaken using a completely randomized design with measurements repeated in time. A quadratic response was observed reaching maximum values as the levels of nitrogen fertilization increased for green forage biomass, green leaf biomass, green stem biomass (5,172.9; 4,146.3; 1,033.9 kg ha(-1) cycle(-1), respectively), forage total density (179.1 kg ha(-1) cm(-1)), canopy height (36.8 cm) and live material/dead material ratio (4.0) at levels 896; 934; 797; 879.2; 751.4 and 1,161 kg ha(-1) year(-1) of N, respectively. For all variables, oscillation was observed between the grazing cycles studied. Nitrogen fertilization has a positive response on the biomass components and canopy structure of massai grass.