Produtividade de forragem e morfogênese de Brachiaria brizantha cv. Marandu sob níveis de nitrogênio

The effect of nitrogen levels (0, 60, 120, 180 and 240 kg of N ha) on green dry matter (GDM) yield and morphogenetic and structural characteristics of Brachiaria brizantha cv. Marandu, was evaluated under field conditions. Nitrogen fertilization increased significantly (P<0.05) GDM yields, tillering, senescence and grass morphogenetic and structural characteristics. Maximum GDM yields, leaf elongation rates, leaf length, number of leaves plant and leaf area index were obtained with the application of 221.5; 206.9; 188.6; 180.5 and 205.5 kg of N ha, respectively. The nitrogen efficiency utilization was inversely proportional to the increased nitrogen levels.