Produtividade da forrageira Urochloa brizantha (Stapf) Webster e estoque de carbono em um sistema silvopastoril

Abstract

Aiming to find multipurpose alternatives for land use and integrated productive systems potential, silvopastoral systems are viable alternatives, considering environmental, social and economic benefits. Considering the necessity for studies related to integrated systems, this study had as objective to evaluate carbon stock and productivity from Urochloa brizantha (Stapf) Webster in two different moments (drought and rainy), in a 5 year silvopastoral system, located in Cachoeira Dourada-GO. For biomass productivity evaluation, samples were collected in two different moments considering the seasonality. Structural sampling arrangement consisted on six blocks from Eucalyptus urograndis. A wooden frame (0,25m²) was used, and the forage was collected close to the soil. After collection, the material was dried until constant weight. For carbon stock quantification, dried biomass was converted, considered 0,47 factor. For average comparison Tukey test (5%) was used. Samples collected at 08 and 12 meters away from tree rows showed higher biomass productivity, due to less shading intensity. The highest productivity was found in dry season. Forage above ground biomass carbon stock totalized 0,404 Mg ha-1 for both periods.