Impact saline water irrigation on soil salinization processes in the Southern Bug and Kamianska irrigation systems

Abstract

In Ukraine, irrigation development is hampered by a shortage of high-quality irrigation water. Irrigation with mineralized irrigation water causes soil salinization, which negatively affects crop productivity, soil quality, and surface water conditions. The purpose of this article is to analyze the impact of irrigation water of different mineralization on soil salinity in the Southern Bug and Kamianske irrigation systems. The field and laboratory studies used the methods and criteria of the salinity laboratory of the US Department of Agriculture and the Food and Agriculture Organization. The studies showed that irrigation is carried out with water that has an average risk of soil salinity (ECw = 0.7-3.0 dS/m). At the same time, there is some spatial differentiation in the quality of irrigation water. The lands of the Southern Bug irrigation system are irrigated with water with an electrical conductivity of 0.90-1.07 dS/m, and the lands of the Kamianska irrigation system are irrigated with water with an electrical conductivity of 1.86-2.65 dS/m. The mineralization of irrigation water determines the degree of soil salinity. While the soils of the Southern Bug irrigation system are not saline (ECe is less than 2.0 dS/m), the soils of the Kamianske irrigation system have a significant accumulation of salts (ECe reaches 5.5 dS/m). According to the Food and Agriculture Organization classification, such soils are classified as saline. Analysis of the salinity tolerance of individual crops showed that any crops of any salt tolerance can be grown on the irrigated lands of the Southern Bug irrigation system. And on the lands of the Kamianske irrigation system, only moderately sensitive and least sensitive crops to soil salinity can be grown without loss of yield. The conducted research allows us to adjust the structure of sown areas and the structure of crop rotations in terms of salt tolerance of certain crops.