Características morfológicas e produtivas e a composição química do capim-Mombaça irrigado e fertilizado ou não com nitrogênio, sob pastejo

Abstract

The experiment was carried out from September 2010 to September 2011, with the objective of evaluating the accumulation of forage mass, morphology and chemical composition of Mombaça grass (Panicum maximum cv. Mombaça) irrigated and fertilized with nitrogen doses in the seasons, under rotational grazing. Experimental design used was a randomized block with split plot design with four replications and four treatments: 0 kg N ha-1year, 200 kg N ha-1year, 400 kg N ha-1year and 800 N ha-1year. Subplots were evaluated in seasons (spring, summer, autumn and winter). The higher dry matter accumulation was obtained at the highest dose of N and in spring and summer. The fertilizer N, especially in higher quantities, provides the highest percentage of leaf blade and its absence provides a higher percentage of dead material. Regardless of N, higher percentages of leaf blade and lower of dead material were obtained in spring and summer, as well as leaf-stem ratio. The N improved the quality of the Mombaça grass by increasing the CP. The in vitro digestibility of dry matter was not different, but presented high values since the grazing rotation was high Overall, the summer had the best forage quality, most obviously in the highest N doses (400 and 800 kg). High doses of N associated with a correct management of grazing promote greater production and improve the nutritional value of Mombaça grass under rotational stocking.