基于同位素示踪的夏玉米土壤水分动态变化规律  

Soil Moisture Dynamic Variation Law of Summer Maize Based on Isotopic Tracing

作　　者：孙宁霞[1] 马英[2] 胡晓农[1] 宋献方[2] 童菊秀[1] 

机构地区：[1]中国地质大学(北京)水资源与环境学院,北京100083 [2]中国科学院地理科学与资源研究所,北京100101

出　　处：《灌溉排水学报》2014年第4期256-260,共5页Journal of Irrigation and Drainage

基　　金：国家自然科学基金项目(41101029);国家重点基础研究发展规划项目(973)(2010CB428805)

摘　　要：基于田间定位监测和室内实验，利用氢氧稳定同位素示踪法，研究了北京大兴区夏玉米生长期间土壤水动态变化规律，并分析了当地降水和土壤水稳定同位素变化特征。结果表明，研究区大气降水线斜率明显小于全球大气降水．土壤水占δ^18O、δD平均值均小于降雨δ^18O、δD平均值。蒸发导致同位素的富集。玉米生长期间0～60cm土层土壤含水率季节变化明显，为活跃层，60～120cm土层为次活跃层，120～200cm土层土壤含水率趋于稳定。0～50cm土层土壤水δ^18O、δD由表层到深层逐渐减小，且季节差异明显。50～200cm土层土壤水δ^18O、δD随深度增加而减小，季节差异降低。Stable hydrogen and oxygen isotopes were used as tracers to study the dynamic change of soil moisture through field monitoring and laboratory experiments during the summer maize growth in Daxing district of Beijing, and the change characteristics of stable isotopes of precipitation and soil moisture were analyzed. The results showed that the slope of the local meteoric water line was less than the slope of the global meteoric water line, and the average values of δ^18O and δD of soil water were less than those of precipitation. Evaporation resulted in isotope enrichment. The seasonal soil water content of 0 - 60 cm in depth changed actively during the growth of the summer maize and 0-60 cm in depth was the active layer. Soil water content of 60-120 cm in depth was sub-active layer while 120-200 cm in depth tended to be stable. δ^18O and δD values of soil water in 0-50 cm gradually decreased from surface soil to deep soil and seasonal change was obvious. δ^18O and δD values of soil water in 50-200 cm decreased as the increase of soil depth, and the seasonal difference reduced.

关 键 词：土壤水 氢氧稳定同位素 水分运移 夏玉米 

分 类 号：S513[农业科学—作物学] S152.7