Influência de Pterodon emarginatus Vogel sobre atributos físicos e químicos do solo e valor nutritivo de Brachiaria decumbens Stapf em sistema silvipastoril

sustainable cattle beef production has been associated with woody trees species in grassland area. this study aimed to evaluate the influence of sucupira branca trees (pterodon emarginatus) in physical and chemical properties of soil and on the quality of forage in silvipastoral systems. the study was carried out in nioaque-ms, brazil. in areas occupied with grassland of brachiaria decumbens , predominantly shaded by trees of sucupira - branca, five adult trees had been chosen, in the surroundings of which were drawn six transects leased to angles of 60o between each other. at intervals of five meters along these transects were centralized sampling plots 30 m away, collecting samples from around litter, grass and soil. forage was analyzed for crude protein (cp), neutral detergent fiber (ndf) and in vitro dry matter digestibility (ivdmd). for the soil the studied attributes were: bulk density, macroporosity, microporosity, total porosity, penetration resistance, levels of exchangeable magnesium and potassium. the data were analyzed by simple regressions and correlation. it was concluded that: the organic material in the litter affects positively the physical attributes of soil, improving structural quality; and the presence of trees affects the nutritional value of grass, allowing increased levels of cp and ndf and reducing ivdmd.