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黏土夹层影响着土壤水盐运移及分布,为了研究在含黏土夹层的土壤中进行微咸水灌溉时土壤的水盐运移规律,进行了春小麦微咸水灌溉大田试验,并在此基础上运用数值模型对土壤盐分累积趋势进行了模拟预测。结果表明,黏土夹层对土壤水盐运移具有显著的阻碍作用,黏土夹层以上土壤平均含水量、含盐量呈随灌溉水矿化度增大而增加的趋势,黏土夹层以下各处理土壤水盐分布几乎不受微咸水灌溉的影响;大定额冬溉洗盐后,各处理0～70 cm土层最大积盐率仍高达65.7%,部分盐分滞留在黏土夹层以上;土壤盐分分布预测结果表明,微咸水连续灌溉5 a后,灌溉水矿化度为4和5 g/L的处理土壤盐渍化倾向明显,不宜在含黏土夹层地区长期使用矿化度>3 g/L的微咸水进行灌溉,否则将对土壤环境产生严重危害。
In order to study the law of water and salt transport in the soil with brackish water in the soil with clay interbed, the experiment of field irrigation with brackish water of spring wheat was carried out. On the basis of this, The numerical model was used to simulate the trend of soil salinity accumulation. The results show that clay interbed has a significant hindrance to the movement of soil water and salt. The average soil water content and salinity above the clay interbed increase with the salinity of irrigation water. Soil water and salt The results showed that the maximum salt accumulation rate in 0 ~ 70 cm soil layer was as high as 65.7%, and some salt remained above the clay interbed. The results of soil salt distribution showed that After 5-year continuous irrigation with brackish water, salinities of 4 and 5 g / L of irrigation water are obviously affected by soil salinization. Therefore, it is not advisable to use salty salinity> 3 g / L for long-term in clay- Water irrigation, otherwise it will have a serious harm to the soil environment.