控制灌溉稻田CH_4排放的影响因子分析  

Influence Mechanism of Controlled Irrigation on CH_4 Emissions From Paddy Fields

作　　者：侯会静[1] 杨士红[2] 徐俊增[2] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]河海大学水利水电学院,南京210098

出　　处：《节水灌溉》2016年第8期70-75,共6页Water Saving Irrigation

基　　金：国家自然科学基金项目(51309192);中央高校基本科研业务专项基金项目(Z109021510)

摘　　要：为了揭示水稻控制灌溉对稻田CH4排放的影响机理,本文采用静态暗箱-气相色谱法对控制灌溉稻田CH4排放进行原位观测,同时观测土壤水分、表层土温和氧化还原电位(Eh)等影响因子,定量分析控制灌溉稻田CH4排放通量与影响因子间的关系。结果表明,控制灌溉稻田田表水层消失后的微弱脱水状态导致了CH4短暂的剧烈释放,CH4排放的峰值大多出现在土壤接近饱和状态(土壤充水孔隙率为99.0%~99.8%)时;控制灌溉稻田CH4排放通量与表层5cm土温之间无显著相关关系(p>0.05);CH4的剧烈释放必须在土壤Eh下降到-100^-150mV,控制灌溉稻田不适宜CH4的产生;控制灌溉稻田CH4集中排放阶段(水稻移栽后21d内)的通量值与土壤Eh值呈极显著负指数相关关系(p<0.001)。不同灌溉模式调控下的土壤水分状况是导致稻田CH4排放显著差异的主要因素。In order to study the effects of controlled irrigation （CI） on seasonal variations of ca4 emissions from paddy fields, CH4 e- missions from CI paddy fields were investigated by the method of static chamber/gas chromatography. Soil moisture, soil tempera- ture and soil redox potential （Eh） were also measured. The quantitative relationships between CH4 emissions and affecting factors were analysed. The weak soil drying led to a short sharp release of CH4 emissions from CI paddy fields. The peaks of CH4 emissions from the CI paddy fields were observed at the WFPS ranging from 99.0% to 99.8%. No significant correlation was found between soil temperature and CH4 emissions （P〉0. 05）. The high emissions of CH4 were observed at soil Eh ranging from 100 to --150 mV, and the conditions of soil Eh in CI paddy fields were not suitable for the production of CH4. A significantly negative exponential relationship （p〈0. 001） was observed between soil Eh values and high CH4 emissions observed within 21 days after rice transplanting in CI paddy fields. The soil water status under different irrigation modes of rice is the main factor that lead to a significant difference between CH4 emissions.

关 键 词：灌溉 排放 CH4 稻田 影响因子 

分 类 号：S274.3[农业科学—农业水土工程]