微咸水微润灌溉下土壤水盐运移特性研究

发布时间：2018-06-13 09:31

本文选题：矿化度 + 入渗　；参考：《农业机械学报》2017年01期

【摘要】：为探明土壤水分和盐分在利用微咸水进行微润灌溉条件下的运移情况,采用室内土箱模拟试验方式,设置2.0、2.5、3.0、3.5、5.0 g/L 5种不同矿化度处理,以蒸馏水处理作对照,共入渗72 h。结果表明:入渗结束时在不同方向上的最大运移距离随矿化度增大呈先增大后减小趋势,在3.0 g/L处理下达到最大值,且微咸水处理的湿润锋运移距离均大于蒸馏水处理;将累积入渗量代入Kostiakov入渗公式,入渗系数随矿化度的增大呈先增大后减小趋势,入渗指数不断减小;土壤电导率以微润带为轴心向四周不断增大,在湿润锋处达到最大值,脱盐区与湿润体形状相关,呈圆环状分布;入渗结束后土壤剖面平均含盐量与蒸馏水处理之间无显著性差异,脱盐半径随矿化度的增大呈线性递减趋势;利用微润灌进行灌溉,土壤盐分存在表聚和底聚现象,且表层积盐更为严重。
[Abstract]:In order to find out the migration of soil moisture and salt under the condition of micro-moisture irrigation with brackish water, the indoor soil tank simulation test was carried out, and five different salinity treatments were set up, I. e., 2.0 ~ (2.5) ~ 3.0 ~ 3.5g / L ~ (5.0) g / L, compared with distilled water for 72 h. The results showed that the maximum migration distance in different directions at the end of infiltration increased first and then decreased with the increase of salinity, and reached the maximum at 3.0 g / L, and the migration distance of wetting front in brackish water treatment was larger than that in distilled water treatment. The cumulative infiltration amount was replaced by Kostiakov infiltration formula. The infiltration coefficient increased first and then decreased with the increase of salinity, and the infiltration index decreased continuously, and the soil conductivity increased continuously with the micro-wetting zone as the axis, and reached the maximum at the wetting front. The desalination area was related to the shape of the wetted body and distributed in a circular pattern. There was no significant difference between the average salt content in the soil profile and the distilled water treatment after infiltration, and the desalination radius decreased linearly with the increase of salinity. The surface salt accumulation is more serious.
【作者单位】：西北农林科技大学水利与建筑工程学院;西北农林科技大学水土保持研究所;北京市水科学技术研究院;
【基金】：“十二五”国家科技支撑计划项目(2015BAC01B03) 陕北水蚀区植被功能调控技术与示范项目(2015BAC01B03)
【分类号】：S152.7

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