Adubação nitrogenada e alturas de resíduos pós pastejo em capim aruana

Abstract

The objective of this work was to evaluate the production and composition of aruana grass submitted to increasing doses of nitrogen and different heights of residue after grazing. The experiment was developed at the Federal University of Grande Dourados, on Dystroferric Red Latosol. The forage used was the aruana cultivar (Panicum maximum), sown on 01/12/2017. The treatments were composed of five doses of nitrogen 0, 75, 150, 225 and 300 kg ha -1 , allocated in the plots and in the subplots two heights of post-grazing residue of 20 and 30 cm. The experimental design was a randomized block with subdivided plots and four replicates. Each plot had an area of 36 m², and the subplots 18 m². The source of Nitrogen used was urea with 45% N. The management was performed through grazing simulation. Nitrogen fertilization provided an increase in the accumulation of dead matter. There was no effect on the production of green matter (MV), dry matter (DM), leaf dry matter (MSF), dry matter stem (MSC) and leaf / stem. The composition of the pasture was not affected by nitrogen fertilization. The height of post-grazing residue of 20 cm increased the production of MV, MS, MSC and MSM, but had no effect on SPS, leaf / shoot and pasture composition. Nitrogen fertilization in increasing doses does not influence the DM production of the forage Panicum Maximum cv. aruana, its bromatological composition does not show great changes under fertilization and different heights of residue after grazing. The lower residue after grazing raises the production of DM.