咸淡轮灌土壤水盐运移特征研究

为了寻求合理微咸水农田灌溉方法,进行了不同咸淡轮灌模拟试验,分析了累积入渗量、湿润锋、土壤含水量、土壤含盐量、盐分浓度和钠吸附比的变化特征,结果表明咸淡咸轮灌方式下土壤入渗能力较大,且脱盐区内脱盐率比淡咸咸的高,而淡咸咸轮灌方式下同一土层土壤含水量高。此外,灌2次咸水与1次相比土壤盐分浓度增加不大。而低SAR的微咸水对碱化土的改良有一定作用。

Research of Soil Water and Salt Trasport Feature For Alternative Irrigation of Fresh and Saline Water

As one important source of solving shortage of the water resources problem for irrigation, the slight saline water is widely concerned. For the sake of researching the method of using slight saline water to irrigation, the infiltration tests with different alternative irrigation of fresh and saline water are conducted. The cumulative infiltration, wetting front distance, water content profile features, salt content profile features, salt concentration and sodium absorption ratio of the soil are analyzed. The experimental results indicate in the saline-fresh-saline way, the capacity of soil irrigation is greater. In this way the ratio of washing salt is higher than in the fresh-saline-saline way. But in the fresh-saline-saline way the soil water content is greater. In addition the salt concentration of using two times saline water is not more than that of using one time. And the slight saline water with low sodium absorption ratio is useful for alkalinity soil improvement.