Características estruturais e produtivas de Brachiaria decumbens Stapf. em monocultivo e em sistemas silvipastoris, na Zona da Mata de Pernambuco

Abstract

The aim of this study was to evaluate the structural and productive responses of Brachiaria decumbens Stapf. pastures under monoculture and silvopastoral systems (SPS) in Pernambuco Forest Zone. Also was studied the relationships among structural and productive characteristics of Brachiaria decumbens Stapf. pastures with leaf area index (LAI) and light interception (LI) estimated by indirect methods. The experimental treatments were: i) B. decumbens Stapf. + Mimosa caesalpiniifolia Benth.; ii) B. decumbens + Gliricidia sepium (Jacq.) Steud. and iii) B. decumbens under monoculture, in randomized block design with three replications. Measurements were proceeded at 5 different points (0, 2, 4, 6 and 8 m away from the tree legume rows), and randomly in monoculture system. Following measurements were taken: forage mass (kg of DM ha- 1), forage density (kg of DM ha-1 cm-1), average height (cm) and compressed height. Also LAI, LI, mean leaf angle (MLA) and extinction coefficient (K) of light, estimated by indirect methods. Higher values (P≤0,05) of forage mass in all experimental treatments, as well as average height and compressed sward and LAI and LI for Braquiaria in monoculture system were obtained in the rainy season of the year. Most correlations between LI and LAI with canopy height and forage mass presented low magnitude. In SPS there is influence of the tree component on most pasture characteristics as the distance of the rows of trees.