SYSTEMATIC STUDY OF CURRENT MELIORATIVE CONDITION AND SALINISATION OF IRRIGATED LANDS IN ZHETYSAI DISTRICT OF TURKESTAN PROVINCE

Abstract

This study presents a comprehensive assessment of the meliorative condition and soil salinization of irrigated lands in Zhetysay District, Turkestan Province. The research investigates the effectiveness of modern irrigation technologies, including drip and subsurface irrigation, alongside vertical drainage systems. Field observations, well measurements, and laboratory analyses revealed that vertical drainage significantly stabilizes groundwater levels, reduces soil salinity, and enables the reuse of drained water, enhancing irrigation efficiency up to 90–95%. Soil salinity was primarily of sulfate-sodium and chloride-sulfate-magnesium-sodium types. Comparative analysis showed that vertical drainage achieves a uniform meliorative background within 3–5 years, outperforming conventional horizontal drainage in salt removal, groundwater management, and economic return. Effective implementation requires continuous monitoring of soil moisture, groundwater depth, water mineralization, pH, and sodium content. Additional interventions, such as chemical amelioration (gypsum, phosphogypsum, sulfuric acid) and deep soil tillage, further improve calcium-sodium exchange and soil structure. The study highlights that integration of water-saving irrigation technologies with vertical drainage and reclamation monitoring provides a sustainable strategy for managing irrigated lands under arid and semi-arid conditions. These findings offer a scientifically grounded basis for optimizing irrigation practices, preventing secondary salinization, and ensuring long-term agricultural productivity in water-limited regions.