The Effects of the Chemical Components of Soil Salinity on Electrical Conductivity in the Region of the Delta Oasis of Weigan and Kuqa Rivers, China

In order to assess the effects of chemical properties of soil salinity on electrical conductivity of 1:5 soil/water extract (EC1:5), the study focused on revealing the main chemical factors contributing to EC of soil extracts and their relative importance. The relationship between EC1:5 and the chemical properties of soil salinity in the delta oasis of Weigan and Kuqa rivers, China, were studied using path coefficient analysis, a path analysis method. We studied each key element affecting EC1:5 either directly or indirectly. The results obtained show that the salt content, total dissolved solids (TDS), and the sum of the sodium ion concentration and the kalium ion concentration are the most influential factors on 1:5 soil/water extract (EC1:5) in the 0–10 cm and the 30–50 cm soil layer. The results show that the sequence of direct path coefficients in the 0–10 cm and the 30–50 cm soil layers on soil conductivity is TDS→Na+ +K+→Salt content→Ca2+→Cl−→the sodium dianion ratio (SDR)→pH→SO42−→HCO3−→Mg2+ the soluble sodium percentage (SSP)→sodium absorption ratio (SAR) and TDS→Salt content→Na+ +K+→Ca2+→SDR→Mg2+→HCO3−→SSP→pH→SO42−→SAR→Cl−. The salt content, chlorine ion, and SAR are the main factors affecting 1:5 soil/water extract (EC1:5) in the 10–30 centimeter soil layer. The order of direct path coefficients result is as follows: Salt content→Cl−→SAR→SSP→TDS→Ca2+→Mg2+ =SO42−→HCO3−→pH→SDR→Na+ +K+. Moreover, the effects of HCO3−, pH were very weak. Though the direct path coefficients between EC1:5 and SAR, SO42− and Ca2+ 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. The models of the different soil layers were structured separately. Evidences showed that multiple regression relations between EC1:5 and most of the primary factors had sound reliability and very good accuracy. The research results can serve as a reference to the scientific management amelioration and utilization of saline in the Delta Oasis of Weigan and Kuqa rivers.