[Characterization of CH4, N2O emission and selection of rice cultivars in double cropping rice fields].

Methane and nitrous oxide emission fluxes of rice cultivars in the double cropping rice fields were measured by static chamber-gas chromatography in field experiments. The results showed a single-peak pattern in seasonal variations of methane emission and a double-peak pattern in variations of nitrous oxide emission for the early season rice, and a single-peak pattern in variations of both methane and nitrous oxide emission for the late season rice. There was significant difference among the rice cultivars in the average emission fluxes of methane and nitrous oxide during the whole growing season.