Research on the Relationship between the Content of Salt in Soil and the Electric Conductivity in Coastal Area of Tianjin

[Objective] The conversion method between the salinity in he Tianjin Binhai saline area soil(Na+-Cl-type) and the electrical conductivity was established.[Method] The content of salt soil was determined with the method of dried residue and the result was compared with the salinity calculated with the formula of electrical conductivity to verify the validity of their relationship.[Results] The method of measurement of the conductivity of soil extracts was simple,fast and accurate.In a certain range of salinity in soil,there was a linear relationship between the conductivity and salinity.The measurement and analysis indicated that the regression formula of the conductivity and salinity in the Tianjin coastal saline zone was:y (%)=0.003 3EC5:1-0.673 6,and the tested result r=0.991 7,with a significant level.And also,the empirically testing results showed that the average error between the formula calculation and dried residue method was 3.88%,which met the requirement of precision in practical production.Through the comparison with other empirical formula and analysis,the application of the method was with high practical value in Bohai Sea saline are [Conclusion] When the salinity in soil exceeded 1.6% or 2.0%,it was proposed the method of dried residue in evaluation of salinity would be much better.