Assessing the Impact of Reservoirs Hydromorphic on Soil Textural Transformation and Salinization in Arid Regions of Uzbekistan

Abstract

This study was conducted to investigate the changes in soil granulometric composition and salinization in soils that are affected by a water reservoir and prolonged hydromorphic processes. Soil samples were collected at a distance of 500, 2000, and 3000 meters from the Kattarkurgan reservoir. In laboratory, water-soluble salts, Cl⁻, SO₄²⁻, HCO₃⁻, pH, and EC were measured. The results revealed that shallow water tables were being 85, 110, and 155 centimeters at sampling points, respectively. The physical clay content of irrigated soils in sampling points increased from 42.8% to 57.7%, revealing an alteration in granulometric composition from medium loam to heavy loam. Under these conditions, the accumulation of water-soluble salts has become intense with its values ranging from 0.214% to 1.338%, which corresponds to a progression from slight to high salinization. The morphological characteristics of the irrigated soils changed under the influence of prolonged moisture, with a distinct light bluish coloration, strong compaction, high moisture content, heavy loam texture, and a structureless profile being pronounced. Furthermore, the features typical of marshy soils, such as Fe, Al and Mg mottles, and salts and carbonates distributed throughout the soil layers in the form of spots and traces were identified. Most importantly, this study unveils that the irrigated soils around the water reservoir are undergoing an increase in physical clay content within their granulometric composition, and excessive accumulation of water-soluble salts.