Composição bromatológica de cultivares do capim buffel em diferentes estações do ano submetidos à adubação nitrogenada

Abstract

This work aimed to evaluate the bromatological composition of Buffel grass cultivars in different seasons, subjected to nitrogen fertilization. The research was carried out at Experimental Farm EPAMIG in Nova Porteirinha-MG, from November 2008 to May 2009, in order to evaluate the effect of nitrogen fertilization on the bromatological composition of three cultivars of Buffel grass, and the effect of the seasons on them. The experimental design was in randomized blocks (RBD) in a factorial scheme 3 x 4 (three cultivars of Buffel Grass - Cenchrus ciliaris cv. Grass, C. ciliaris cv. PI 295 658 and C. ciliaris cv. Áridus, and four doses of nitrogen (0, 75, 150 and 225 kg/ ha) with three replications, totaling 36 experimental units.. Nitrogen fertilization was split in three applications (one third of the total dose) during the rainy season, after cutting of standardization, using as source of nitrogen fertilizer ammonium sulphate and applied at throw. For purposes of statistical analysis, the mean value of December/2008, January/2009, February/2009 we used characterizing the summer and March/2009, April/2009 and May/2009 characterizing the autumn. There was no effect of the interaction between the factors doses of nitrogen and cultivar. The application of Nitrogen fertilization, in the summer, provided a 30% increase in Crude Protein content, reaching maximum content of 10.90% in the dosage of 144.12 kg N/ha. The PI295658 cultivar, in the summer showed lower Crude Protein, neutral detergent insoluble nitrogen and higher contents of total carbohydrates than the Grass and Áridus cultivars. In the autumn, crude protein content was influenced by nitrogen fertilization, reaching the highest value in the dosage of 225kg N/ha. The cultivars Áridus and PI295658 showed higher values of neutral detergent insoluble nitrogen than Grass cultivar.