Adubação nitrogenda e potássica na produção de massa seca e composição bromatológica do capim-xaraés

Abstract

In grazing systems, nitrogen fertilization has presented productive response lower than planed due to inadequate potassium input, suggesting an interaction between absorption and the use of those nutrients. This work aimed to evaluate the nitrogen and potassium fertilizer on Brachiaria brizantha cv. Xaraés nutrition and yield. The experiment was conducted in a greenhouse at Embrapa Rice and Beans. The experimental design was randomized blocks with four replications in a 4 x 4, consisting of four doses of nitrogen (N): 0, 25, 50 and 100 mg dm-3, and four doses of potassium (K2O) 0, 25, 50 and 100 mg dm-3 . The nitrogen and potassium contribute positively to increasing dry matter production, tiller number, foliar area and crude protein contents. However, both reduce NFD content and nitrogen reduces ADF content of “xaraés” grass.