Estudo do comportamento das trocas de dióxido de carbono sobre uma cultura de arroz irrigado por inundação no sul do Brasil

Abstract

Brazilian agriculture is recognized as one of sectors most fundamental to the Brazilian economy. However, agriculture is an important source of greenhouse gases, accounting for 75 % of CO2 emissions, 91 % of CH4 emissions and 94 % the emissions of N2O no country. In these estimates, the irrigated rice paddy makes an important contribution. The objective of this study is to compare the estimates of carbon dioxide flux (CO2) between the irrigated rice paddy and the atmosphere in a farm in southern Brazil, municipality of Cachoeira do Sul. Two techniques for estimating surface CO2 fluxes are used for ecosystem respiration: Eddy Covariance (EC) and solo chamber. When comparing the techniques, the accumulated values of CO2 in irrigated rice, obtained by the soil chamber, were between 30 and 60 % higher than those obtained by EC. This study allows us to understand the dynamics of CO2 exchanges in flood-irrigated rice cultivation in southern Brazil.