摘要
针对黄淮海冲积平原土壤剖面中粘土夹层普遍存在的现象,在典型易盐渍区开展模拟易盐农田常规种植条件下水盐运移的大型土柱实验,基于长达20年的长系列监测数据分析,系统研究易盐渍区不同土体构型和地下水位等代表性条件下的土壤水盐运移规律和粘土夹层的影响特征。研究结果表明:粘土层有良好的保水和隔盐能力,尤其对表土积盐的抑制效果显著,且抑盐效果随粘土层厚度增加而提升;含粘土夹层土体表土积盐的地下水埋深范围更小,表土积盐高峰出现在1 m左右地下水埋深,全剖面粉砂壤土土体的表土积盐高峰出现在1.5 m左右地下水埋深、且地下水埋深小于阈值2.5 m时极易引发盐渍害;粘土夹层对土壤盐分运移有双重影响,在其可抑制表土积盐的同时,粘土层部位易积盐,水土资源利用过程中需监测和防控其次生盐渍化风险。
Large-scale soil column experiments for simulation water-salt movement in clay interlayers under normal growing conditions were carried out in an easily-salinized region for different textures of soils and groundwater conditions in the Huang-Huai-Hai alluvial plain of China.In this study,the 20-year measurement was analyzed to examine the effect of clay interlayers on soil water-salt movement in easily-salinized regions.Results show that the clay interlayer has a significant positive effect on the water-holding capacity in the soil and acts as a filter obstructing the salinity infiltration.This is especially true for restraining the penetration of surface accumulated salts.The thicker the clay interlayer is,the greater the effect will be.The range of depth to groundwater is likely to be smaller in the area with surface accumulated salts and clay interlayers around 1.0 m than that with silt loam soils around 1.5 m.And in the latter case,the salinization of soils is easily induced when the groundwater level is lower than a threshold value of 2.5 m.The amount of accumulated salts is found to be higher in clay interlayers than that in silt loam soils.Thus,proper monitoring and measures are necessary to prevent the secondary salinization of soils in the practice of water resources management.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2011年第4期495-501,共7页
Advances in Water Science
基金
公益性行业(农业)科研专项经费资助项目(200903001)
国家重点基础研究发展计划(973)资助项目(2010CB429001)~~
关键词
易盐渍区
粘土夹层
水盐运动
双重影响
easily-salinized region
clay interlayer
water-salt movement
dual influence
