Intensidades de cortes para o capim-buffel em condições semiáridas

Abstract

Despite the recognized potential of buffel grass for cultivation in Brazilian semi-arid climates, little is known about grazing management for this forage species. Thus, buffel grass plants are often subjected to severe grazing conditions, which lead to the need for studies on grazing intensity tolerated by this plant, as well as its morph-physiological and qualitative response to different management strategies. The experiment was conducted between October 2013 and April 2015, to evaluate intermittent management strategies (residue of 10 or 20 cm) for the buffel grass in the semiarid conditions of northern Minas Gerais. Experimental design was randomized blocks, with two treatments: I 10 (residue 10 cm) and I 20 (residue 20 cm), with cutting frequency of 50 cm. Evaluations consisted of total dry matter production (MST) and morphological components: leaf (MSLF), stem (MSC) and dead material (MSM) of buffel grass. In these samples were also determined the blade: stem ratio (RLC), the green forage: dead forage ratio (RVM) and population densities of total (DPT), vegetative (DPV), reproductive (DPR), live (DPVV) and dead (DPM) tillers, as well as the growth rate (TC), the rain use efficiency (EUC) and the chemical composition of the forage (PB, FDN, FDA and HEM). The data were grouped and analyzed as means of five evaluative cuttings. The management I 20 (lower intensity cutting) showed increased production of MSF (1,584, 43 kg ha-1 of dry matter), RLC (3.13), RVM (2.98), DVT (93.01 kg ha-1 cm-1 ) and DVLF (52.81 kg / ha.cm), but lower MST productivity (2790.32 kg ha-1 of dry matter). The residue of 20 cm in height (I 20) provided the highest amount of leaf blades, consequently, higher PB content (9.49%), and lower FDN (63.13% ) and FDA (34.99%) percentages. Thus, it is concluded that the buffel grass must be handled with a cutting strategy of leaving a 20 cm residue, so as to obtain fodder productivity with better morphologic and chemical composition.