Trocas gasosas de CH4 E N2O entre solo e atmosfera em diferentes tipos de cobertura nos municípios de Belterra e Santarém, Pará

Abstract

The change of use and soil management is occurring in a dynamic and intensive, especially in the Amazon region, which can result in source or sink of greenhouse gases into the atmosphere. This study aimed to quantify gas exchange of methane (CH4) and nitrous oxide (N2O) from soil and atmosphere in different types of coverage, and examine environmental variables regulating gas exchange in the areas sampled. These measurements were made using cameras installed in the field, and then the samples analyzed by gas chromatography (N2O and CH4) in the laboratory. There was no significant difference in the flow of CH4 by the effects of changing land use in agricultural fields of soybeans (0,23 ± 0,08 mg-C/m2/h), pasture (0,31 ± 0,18 mg-C/m2/h) and poultry (0,42 ± 0,17 mg-C/m2/h) surrounding the BR-163 and PA-370. Statistical difference was found between the flow of N2O related to the type of ground cover, where the flow of poultry (19,57 ± 0,76 mg-N/m2/h) was lower than the pasture (36,81 ± mg-N/m2/h ± 1,84) and agriculture (40,08 ± 1,30 mg-N/m2/h). Difference between CH4 fluxes found in soybeans in no-tillage (0,29 ± 0,11 mg-C/m2/h) compared to conventional tillage (0,11 ± 0,07 mg-C/m2/h) also found differences in N2O flux of tillage (40,7 ± 10,7 mg-N/m2/h) that was higher than the conventional tillage (38,8 ± 10,7 mg-N/m2/h). Faced with changes in land use increasingly common, there is a need to intervene to reduce greenhouse gas emissions or enhance their sinks.