Influência da adubação com npk na produção e composição química de brachiaria brizantha cv mg-4.

Abstract

This work was carried out in the Departments of Soil Science and Animal Science of the Federal University of Ceara, Campus do Pici, Fortaleza-CE, to evaluate the production and chemical composition of Brachiaria brizanta (Hochst ex A. Rich) Stapf. cv. MG-4, when subjected to different combinations of doses of NPK, in a greenhouse. The experiment was composed of sixteen combinations of doses NPK as matrix experimental PueblaII Plan, completely randomized design, with five repetitions. It was used a Argisol Red Yellow Distrophic Arênico and, as a source N, P and K, were used ammonium sulfate and urea, triple superphosphate and potassium chloride, respectively. Cutting uniformity of the plants was conducted at 42 days after germination, to 15 cm from the ground. The first cut of use was made 28 days after the cutting of uniformity to 15 cm from the ground and the second cut of use to 28 days after the first cut of use to 15 cm from the ground. The material collected the first and second cutting wire separated into leaves and stems and put the assessments of dry matter (DM) of the shoot, crude protein (CP) and determine the levels of N, P and K of the leaves and stems. The doses of 360-370-360 g / pot of NPK provide 95% of the increased production of MST observed. There are squared effects of doses of N, at doses of 373, 407 and 317 of N mg/dm3 for maximum production estimated MST, MSF and MSC, respectively. Using up the doses of 360 mg P and K/dm3 of soil, returned to linear effect of doses of P for production of MST and MSF, however, there was no effect on production of MSC. Were obtained linear effects of doses of K on the production of MST, MSF and MSC. The doses of N and K linearly affected the levels of PBF, while P had no significant effect, and the levels of PCBs were not affected by doses of NPK. The levels of PBF were higher than levels found in stems. The phosphate fertilizer and foremost, the nitrogen, caused an increase in the accumulated amount of N, P and K. the increase of nitrogen reduced the level of P in the leaves.