Changes in Soil Salinity at the Chervlenoe Irrigation Massive (Volgograd Oblast) in a Quarter of Century

Abstract

Maps of soil salinity and toxic alkalinity in 2017–2018 were developed for the Chervlenoe irrigation massive of Svetloyarsk irrigation system. These maps were compared with the maps of soils in the virgin state and under irrigation in 1992 and 2006. The massive is located close to the Volga–Don Canal on the northern slopes of the Ergeni Upland (Volgograd oblast). Before irrigation, the soil cover was composed of associations (complexes) of loamy solonetzic light chestnut soils (Sodic Cambisols (Loamic, Ochric, Magnezic, Bathyprotosalilic)) and steppe solonetzes (Endosalic Solonetz (Albic, Loamic, Columnic, Cutanic, Differentic, Ochric, Magnezic)) developed from loesslike loam. The soil cover was strongly transformed by surface leveling during the irrigation system construction, and underwent secondary salinization in the 1970s–1990s because of excessive irrigation water supply. Changes in the soil salinity in the past 20–25 years are discussed. Both favorable (partial salt leaching) and negative (alkalization of topsoil horizons) processes are revealed.