Sward structure and forage accumulation dynamics in pastures of Marandu palisadegrass submitted to grazing intensities and levels of supplementation under continuous stocking

Abstract

In the grassland ecosystem the light interception is the initial step of a sequence of events which results in the forage production. There are a lot of factors that interfere in the process of light interception, and among them, the most expressive ones are related to the leaf area index, the structural characteristics, and the special arrangement of the sward components. Considering the continuous need to solve the doubts concerning the interactions that exist among soil, plant, and animal, this study will be carried out aiming at evaluating the impact of the pasture height and the effect of the supplementation under continuous stocking upon the sward structure, the biomass production, the tillering dynamics, and the forage accumulation in pastures of Brachiaria brizantha cv. Marandu, under soil and climate conditions in Jaboticabal, SP. The experimental period will be from November in 2010 to July in 2011, and from November in 2011 to July in 2012, and it will be divided into two times: water (from November until April) and transition water/drought (from May until July). The experiment will be developed in pastures of Brachiaria brizantha (Hochst ex. A. Rich.) cv. Marandu, in a seven year established area that belongs to the Forage and Grassland section of the Agrarian and Veterinary College/UNESP. The experiment will be performed following a complete randomized design, with two replications. The treatments will correspond to the average pasture heights (15, 25, and 35 cm) and the levels of supplementation (with and without supplement) in the water time, corresponding to a 3x2 factorial. This way, the experiment will present 12 experimental unites or paddocks (3 pasture heights x 2 levels of supplementation x 2 replications) in the water times. In the transition time water/drought, the same 12 paddocks will be used, but, with a lower stocking. The treatments will correspond to the history of the water heights (15, 25, and 35 cm), and the animals will receive 0,6% of the body weight of supplement.Keywords - Brachiaria brizantha, ecophisiology, grassland management, tillering