欢迎访问《应用生态学报》官方网站,今天是 分享到:

应用生态学报

• 研究报告 • 上一篇    下一篇

黄土高原冬小麦田土壤CH4通量对人工降水的短期响应

刘全全1,王俊1**,陈荣荣1,刘文兆2,Upendra M. Sainju3   

  1. (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; 3USDAARS Northern Plains Agricultural Research Laboratory, Sidney, MT 59270, USA)
  • 出版日期:2015-01-18 发布日期:2015-01-18

Short-term response of soil CH4 flux to simulated precipitation in a winter wheat field on the Loess Plateau, Northwest China. 〖STBZ〗

LIU Quan-quan1, WANG Jun1, CHEN Rong-rong1, LIU Wen-zhao2, Upendra M. Sainju3   

  1. (1College of Urban and Environmental Sciences, Northwest University, Xi’an 710127, China; 2Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China; 3USDAARS Northern Plains Agricultural Research Laboratory, Sidney, MT 59270, USA)
  • Online:2015-01-18 Published:2015-01-18

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.
 

Abstract: To understand the short-term response of soil CH4 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 mm. 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 change the soil function from CH4 sink to source by stimulating the activity of soil methanogens during shortterm periods.