Studies on the emission of methane gas (CH 4) in agricultural ecosystems have received attention from the scientific community because it plays an important role in the greenhouse effect. Flood irrigation agriculture, such as irrigated rice, represents a considerable source of methane emissions (from 12 to 26 percent of all the world's anthropogenic CH 4 emissions). Estimates of the CH 4 emissions have also been performed through the vortex covariance technique. Although this methodology makes continuous measurements of methane exchanges between the ecosystem and the atmosphere, failure to collect data can occur because the system is very sensitive, especially to the weather. The filling of the flaws in the methane estimation is essential to obtain a daily or seasonal quantification of the emissions. In this study, different fault-filling techniques were tested in the CH 4 fluxes obtained by the vortex covariance technique on an irrigated rice crop. The experimental data were obtained in Cachoeira do Sul - RS in the period from 11/20/2015 to 04/30/2016. The Look-Up Table (LUT) filling technique, which consists of filling gaps using averages of flow values for periods with similar atmospheric conditions, was, on average, the technique that best filled the methane flux data.
