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本文介绍了用电导法测定盐渍土壤渗透势的方法，并将此法用于测定河西盐渍化土壤和碱茅（Ｐ．ｔｅｎｕｉｆｌｏｒａ）种子萌发期半致死渗透势。结果表明：河西盐渍化土壤浸提液的渗透势（ＯＰ，ＭＰａ）与电导率（ＥＣ，ｄｓｍ－１）呈指数关系，ＯＰ＝－０．０２５ＥＣ１．１９。研究区各类草地渗透势的变化特点是春、秋两季下降，夏季上升。２年生碱茅草地和撩荒地土壤０～１０ｃｍ层渗透势明显高于１０ｍ以下各层，其平均值分别是：－０．３４，－０．３１ＭＰａ；３年生碱茅草地渗透势升高，１０ｃｍ土层平均值为－０．０７ＭＰａ。碱茅种子萌发期的半致死渗透势为－０．９１ＭＰａ。
In this paper, the method for determining osmotic potential of saline soils by conductivity method was introduced. The method was applied to determine the semi-lethal osmotic potential of seed germination of Hexi salinized soils and P. tenuiflora seeds. The results showed that the osmotic potential (OP, MPa) and the conductivity (EC, dsm-1) of the leaching solution of Hexi salinization soil showed an exponential relationship, OP = -0.025EC1.19. The change of osmotic potential of various types of grassland in the study area is characterized by a decrease in spring and autumn and an increase in summer. The soil osmotic potential of 0 ~ 10cm layer in 2-year-old alkali grassland and retiring land was significantly higher than those below 10m, the average values were -0.34 and -0.31MPa, respectively. Soil average is -0.07MPa. Semi-lethal osmotic potential during the germination phase was 0.51 MPa.