Nitrogen fertilization in introduction of Brachiaria brizantha cv. Marandu in Humaitá-AM

Abstract

The low technological input on farms in the south of the Amazon, mainly related to the soil fertility, is one of the main factors that difficult the maintenance of high yields in pastures. Thus, in the present study, we aimed to evaluate the growth of Brachiaria brizantha cv. Marandu submitted to different doses of nitrogen. A field test was carried out on Haplic Cambisol, conventionally prepared and submitted to liming. The plots were arranged under a randomized block design, with four replications, where the treatments were applied, being five levels of nitrogen fertilization: 0, 50, 100, 150 and 200 kg ha^-1 of N. We used parcels of 3 x 4 m, totaling 12 m². The uniformity cut occurred 70 days after sowing, and the nitrogen fertilizer was applied. After 35 days of nitrogen application, the first cut of the plants was performed and after the same interval the second cut was carried out. In both cuts were evaluated the number of tillers, the leaf/stem ratio, the dry mass of the aerial part and height of plants. The dose equivalent to 100 kg ha^-1 of nitrogen provided better growth of Brachiaria brizantha cv. Marandu.