Estudo das técnicas de preenchimento para dados de fluxo de metano em uma área de arroz irrigado por inundação

Abstract

Studies on the emission of methane gas (CH4) in agricultural ecosystems have received attention from the scientific communitybecause it plays an important role in the greenhouse effect. Flood irrigation agriculture, such as irrigated rice, represents aconsiderable source of methane emissions (from 12 to 26 percent of all anthropogenic CH4 emissions in the world). Estimates ofCH4 emissions have also been performed through the eddy covariance technique. Although this methodology makes continuousmeasurements of methane exchanges between the ecosystem and the atmosphere, failure to collect data can occur because thesystem is quite sensitive, especially in the hard weather conditions. The gap filling in the methane data are essential to obtaina daily or seasonal quantification of the emissions. In this study, different gap filling techniques are used to fill the CH4 fluxesobtained by eddy covariance technique in an irrigated rice crop. The experimental data were obtained in Cachoeira do Sul - RS inthe period from 11/20/2015 to 04/30/2016. The Look-Up Table (LUT), which consists of filling gaps using averages of flux valuesfor periods with similar atmospheric conditions, was the technique that best close the gap in methane fluxes data.