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 CH₄ 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 CH₄ emission from paddy fields is 6.20 mg/m²·h. The influencing factors on CH₄ 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 CH₄ emission during the rice growing season is about 173.96kg/hm².