Emissões de gases de efeito estufa em sistemas agropecuários no Norte de Mato Grosso

Abstract

The general objective of this study was to evaluate the emissions of greenhouse gases in agricultural systems. The experiments were conducted in Alta Floresta and Sinop-MT, static cameras were used and syringes for collecting gases, which always happened in the morning. In Alta Floresta emissions were compared N2O and CH4 from managed pastures (MP), unmanaged (UP) and native forest (F) as the reference area. There were simple sampling, over time and intensive sampling, that happened when there was application of nitrogen fertilizer in MP. Higher average flows of N2O were recorded in the MP and the average fluxes of CH4 did not follow a definite trend. In the rainy season was the highest N2O and CH4 fluxes. In intensive sampling observed increase in N2O fluxes and reduction of CH4 fluxes in the following days to nitrogen fertilization. Low levels of nitrogen fertilization resulted in low emissions of N2O. In Sinop were compared monocultures fluxes in forest (F), agriculture (L) and pasture (P) with a system of crop-livestock-forest integration (ICLF). The N2O fluxes were higher in the rainy season than in the dry season. The fluxes from areas F, P, ICLF were smaller than those of L, thus to integrate the three components in the same area and the influence of the forest component in the reduction of fluxes, the ICLF system showed high potential for mitigation N2O emissions.