Methane Flux from a Subtropical Rice Field

It has been confirmed that rice fields contribute a lot to atmospheric methane. The object of this research was to analyse the diurnal changes of CH4 fluxes from a rice field in southern subtropical China in early rice season. The measuring device was a modification of a closed static chamber and gas chromatography. Samples of CH4 were collected from treatments with rice crop plot and bare soil plot at the same time. The results indicated that there are two peaks of variation in diurnal CH4 emissions during the growing season of rice. The average CH4 fluxes in the field appeared in the order of maturity stage (1.96 ± 0.33), booting stage (0.13 ± 0.01) and post-harvest stage (-0.01 ± 0.02) (mg·m-2·h-1). At booting stage, average flux of CH4 was much higher in the plot with rice plants than that of bare soil plot (p