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估计灌溉水质广泛使用的一种方法是1954年美国盐渍土实验室提出的钠吸附比法(见后式(2))这个方法的不足之处在于未考虑含Na_2CO_3高的水对结构上不稳定土壤的影响。近年来,Rhoades(1968,1971),Bower(1965,1967),Caas(1980)等人考虑到灌溉水中碳酸盐的沉淀或土壤硅酸盐矿物析出钙、镁离子对灌溉水钠吸附比的影响,结合土壤淋洗条件,对原先适用于估计灌溉水碱害的方程式进行了修改。
A widely used method to estimate the quality of irrigation water is the deficit of the sodium adsorption ratio method proposed by the American Salinization Soil Laboratory in 1954 (see the formula (2) below). The disadvantage of this method is that it does not take into account the fact that water containing Na 2 CO 3 is not structurally Stabilize the soil. In recent years, Rhoades (1968, 1971), Bower (1965, 1967) and Caas (1980) considered the precipitation of carbonate in irrigation water or the precipitation of calcium and magnesium ions by soil silicate minerals, Influence, combined with the soil elution conditions, the original formula for estimating irrigation water and alkali were modified.