Electrical Conductivity in Soil Extracts: Chemical Factors and Their Intensity

The electrical conductivity (EC) of 1:5 soil-water extract (EC1:5) was studied utilizing path coefficient analysis. The study focused on revealing the main chemical factors contributing to EC of soil extracts and their relative importance. Results showed that the most important factors influencing the EC1:5 of coastal salt-affected soils were the concentration of salt in 1:5 soil-water extract (Sc), Cl-, and the sodium adsorption ratio (SAR), while effects of pH, CO32-, HCO3-, soluble sodium percentage (SSP), and sodium dianion ratio (SDR) were very weak. Though the direct path coefficients between EC1:5 and SO42-, Ca2+, Mg2+, K+, or Na+ were not high, influence of other chemical factors caused the coefficients to increase, making the summation of their direct and indirect path coefficients relatively high. Evidences showed that multiple regression relations between EC1:5 and most of the primary factors (Sc, Cl-, and SAR) had sound reliability and very good accuracy.