黄土高原冬小麦田土壤CH_4通量对人工降水的短期响应  

Short-term response of soil CH_4 flux to simulated precipitation in a winter wheat field on the Loess Plateau,Northwest China

作　　者：刘全全[1] 王俊[1] 陈荣荣[1] 刘文兆[2] Upendra M.Sainju 

机构地区：[1]西北大学城市与环境学院,西安710127 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]USDA-ARS Northern Plains Agricultural Research Laboratory, Sidney, MT 59270, USA

出　　处：《应用生态学报》2015年第1期140-146,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31270484,41171033);教育部科技重点项目(209123);西北大学研究生自主创新项目(YZZ13006)资助

摘　　要：为了解黄土高原旱作农田土壤CH4排放对不同降水事件的短期响应过程,分别在冬小麦拔节期和夏闲期进行了人工模拟降水试验,对1-32 mm不同降水量模拟降水后0-72 h土壤CH4排放通量进行了观测.结果表明：模拟降水后旱作农田土壤CH4排放通量变化特征表现出两种不同的模式：低降水量（1、3和8 mm）处理为波动变化,高降水量（16和32 mm）处理呈单峰型变化.降水后72 h土壤CH4累积通量（CH4-C）与降水量（P）呈显著线性正相关（冬小麦拔节期：CH4-C=2.45P-6.09,R2=0.92,P〈0.01;夏闲期：CH4-C=2.43P-4.73,R2=0.91,P〈0.01）.相关分析表明,土壤CH4通量与土壤含水量和土壤微生物生物量碳含量显著相关,而与土壤温度不相关.少量降水（1-8 mm）可以在短期内促进旱作农田土壤对CH4的吸收,加强土壤作为大气CH4汇的强度,然而这种促进作用也会随降水量的增大和降水的下渗而削弱.较大降水（≥16 mm）可以刺激土壤产甲烷菌活性促进CH4释放,在短期内使旱作农田土壤由单一的汇功能转变为汇源双重功能.To understand the short-term response of soil ca4 flux to different precipitation events in a winter wheat field on the Loess Plateau, we conducted precipitation simulation experiments during winter wheat jointing stage and summer fallow period to measure the soil CH4 flUX in 0 to 72 h after precipitation simulation of 1 to 32 mm. Results showed that CH4 flux during 0 to 72 h fluctuated at 1 to 8 mm of precipitation application and peaked at 16 and 32 ram. Cumulative CH4 flux after 72 h of precipitation （ CH4-C ） increased linearly with the precipitation amount （ P ） （ wheat jointing stage： CH4-C=2.45P-6.09, R2=0.92, P〈0.01; summer fallow： CH4-C=2.43P-4.73, R2= 0.91, P〈0.01 ）. Statistical analysis showed that CH4 flux was also correlated with soil water content and microbial biomass carbon but not with soil temperature. In the long run, small precipitation events （ 1-8 mm） could enhance the intensity of soil CH4 sink and such promoting effect would be weakened with further increase in precipitation amount. However, large precipitation events （ ≥ 16 mm） could c methanogens during hange the soil function from CH4 sink to source by stimulating the activity of soil short-term periods

关 键 词：旱作农田 人工降水 土壤CH4通量 短期响应 

分 类 号：S512.11[农业科学—作物学]