Hydrochemical Assessment of Water Used for Agricultural Soil Irrigation in the Water Area of the Three Morava Rivers in the Republic of Serbia

Abstract

The assessment of the suitability and status of irrigation water quality from the aspect of its potential negative impact on soil salinization and mapping of spatial distribution within the area of the three Morava rivers, which includes the South, West, and Great Morava basins, was the purpose of this research. A total of 215 samples of irrigation water were tested, and their quality was evaluated based on the analysis of the following parameters: pH, electrical conductivity (EC), total dissolved salt (TDS), sodium adsorption ratio (SAR), and content of SO42-, Cl-, HCO3-, CO32-, Mg2+, Ca2+, Na+, and K+. The results showed that the average content of ions was as follows: Ca2+ > Mg2+ > Na+ > K+ and HCO3- > SO42- > Cl- > CO32-. The assessment of irrigation water suitability was determined by calculating the following indices: percentage sodium (Na %), residual sodium carbonate (RSC), permeability index (PI), magnesium hazard (MH), potential salinity (PS), Kelley's index (KI), total hardness (TH), irrigation water quality index (IWQI). Based on Wilcox's diagram, the USSL diagram, and the Doneen chart, it was concluded that most of the samples were suitable for irrigation. Using multivariate statistical techniques and correlation matrices in combination with other hydrogeochemical tools such as Piper's, Chadha's, and Gibbs diagrams, the main factors associated with hydrogeochemical variability were identified.