Evaluation of Correlation and Regression Relationships Between Soil Solution Electrical Conductivity and Major Ion Concentrations

Since the electrical conductivity (EC) of soil solutions directly reflects the total concentration of dissolved ions, it is considered one of the most reliable and widely used indicators for assessing the salt content in the soil. EC parameters, acting as a comprehensive indicator of the content of soluble salts, are closely related to many physicochemical properties of the soil, including food mobility, plant water supply, soil fertility, and long-term productivity of agricultural systems. In this context, identifying ions that directly influence fluctuations in electrical conductivity is fundamental to understanding salinization dynamics, evaluating the effectiveness of Reclamation measures, and developing sustainable soil management strategies. The presented research work was carried out with the aim of studying the degree of influence of the main dissolved cations (Na+, Ca2+, Mg2+, K+) and anions (Cl-, SO42-, HCO3- ) on the electrical conductivity of the soil solution. Pearson analysis was used to determine the intensity of the correlation between EC and individual ions. To determine the relative weight and significance of each variable, the multidimensional linear regression method and standard regression coefficients were used. The combined use of these statistical methods allowed an in-depth analysis of the Ionic factors that control EC changes and the correct separation of large and small factors that affect soil salinization. Statistical analysis showed that the elements with the strongest positive correlation with electrical conductivity are sodium (Na+) and chloride (Cl-). This situation also confirms that these two ions play a dominant role in the accumulation of soluble salts in the studied soils. Although significant positive correlations were also recorded with calcium (Ca2+), magnesium (Mg2+) and sulfate (SO42-) ions, their final effect on EC was poor compared to sodium and chloride. Conversely, potassium (K+) and bicarbonate (HCO3-) ions showed both low standard regression coefficients and relatively weak correlations. This result shows that in modern research conditions, the ratio of these ions in EC oscillations is very limited. In general, the results obtained more clearly reveal the mechanism of influence of the ionic composition of the soil solution on its electrical conductivity and prove that the main driving forces that determine salinity in the studied medium are sodium and chloride. The study also confirms the effectiveness of multidimensional statistical methods when interpreting the chemical properties of soils and looking for the most informative indicators of salinization. In conclusion, we can say that this study provides an important scientific framework for improving the assessment of salinity, developing Reclamation methods and managing irrigation, and supporting the sustainable use of saline arable land. In addition, the presented analytical base can be used in future studies as a useful tool for monitoring soil quality and predicting the risks of salinization in various environmental and agricultural conditions.