Métodos para estimar a massa e a composição morfológica da forragem em dosséis de Capim-Marandu.

Abstract

This study compared three methods of estimative of forage mass and its morphological composition of Urochloa brizantha cv. Marandu (Marandu palisadegrass). Two experiments were carried out at the Experimental Farm Capimbranco, School of Veterinary Medicine, at the Federal University of Uberlândia, which the first one simulated grazing in a deferred pasture and the second, a continuous stocking grazing. In the first experiment, from October 2015 to August 2016, three methods for estimation of forage mass (quadrat, line, and number and weight of tillers) were evaluated in deferred canopies with three initial heights (15, 30 and 45 cm). In the second experiment, from October 2016 to March 2017, two methods for estimation of forage mass (quadrat and tiller methods) were evaluated in canopies with three average heights (15, 30 and 45 cm). The experiments were conducted in a completely randomized design, in a split plot, with four replications. When using the quadrat method, the greater the canopy heights, the greater the forage mass, for both experiments. However, in the second experiment, when using the tiller method, no differences for forage mass were observed among canopy heights. Only in the 45 cm deferred pastures the quadrat method resulted in greater forage mass, than the tiller method. In the first experiment, the tiller method resulted in greater percentage of live leaf and live stem, and a lower percentage of dead material, in comparison to the other methods. The method of estimation of forage mass by the tiller underestimates the amount of dead forage, and overestimates that of leaf blade and stem components.