Methane emission from rice-rape rotation paddy fields and its total amount estimation

Methane emission fluxes from rice-rape rotation paddy fields were measured by the static chamber-gas chromatographic techniques in hilly area of the central Sichuan Basin.The results show that CH_4 emission from paddy fields varies remarkably and seasonally during the rice-growing season,and the peak value of methane emission is presented in the metaphase of rice bearing stage.The average flux of CH_4 emission from paddy fields is 6.20 mg/m2·h.The influencing factors on CH_4 emission from paddy fields are discussed in this paper.The rice plants play a key role in the methane emission during the early growing stage of rice;while the temperature plays a key role in the methane emission during the tassel and mature stage of rice.The total amount of CH_4 emission during the rice growing season is about 173.96kg/hm2