川中丘陵区稻田甲烷排放及其影响因素

Methane emission from paddy fields and its affecting factors in hills of the central Sichuan Basin.

利用静态箱/气相色谱法对川中丘陵区冬水田和水旱轮作稻田进行全生长季CH4排放观测。结果表明,水旱轮作稻田和冬水田CH4排放的季节变化峰值都出现在水稻生长中期,且都有1个典型的排放峰。分析讨论了温度、水稻生物量、耕作制度以及水稻栽培方式等因素对稻田CH4排放的影响。发现川中丘陵水稻生长季节5cm深处地温与稻田CH4排放通量呈显著正相关;水稻植株生长对CH4排放有重要作用;水旱轮作稻田CH4排放通量比冬水田低54.1%～65.1%;冬水田水稻采用强化栽培方式既可提高产量又可减少CH4排放。

Methane emission fluxes from paddy fields growing rice all the year-round and paddy fields growing rice-wheat or rapeseed in rotation were measured with the static chamber-gas chromatographic technique in hills of the central Sichuan Basin.Results show that high CH_4 emission from the paddy fields under rotation and mono-rice cropping appeared in the middle of the rice growing season,and each had a typical peak.Effects of temperature,rice biomass,cropping system and planting model on CH_4 emission from paddy field have been analyzed and discussed.Significant positive relationship was found between 5 cm depths of soil temperature and CH_4 emission.Rice plants played an important role in CH_4 emission from the paddy field.The mean CH_4 emission fluxes from the paddy fields under rotation was 54.1%-65.1% lower than those under mono-rice cropping during the rice growing season.The intensified rice planting model could not only raise rice yield,but also reduce CH_4 emission from the paddy field.