Salt-affected soils of the Rostov lowland (Yaroslavl region): morphology, genesis and dynamics of salinization in the annual hydrological cycle

Available data on salt-affected soils of the Rostov lowland in the Upper Volga region and the Nero lake basin are predominantly based on observations made in the beginning of the last century. Modern studies of potential areas of soils salinization in this region are absent. As a result of the conducted investigations considering long-term stages of the groundwater level decreasing within the area of Rostov lowland on a background of the known trends of the climate change, the question on the salinization phenomenon is still opened. Following the results of the second cycle of monitoring investigations in 2016-2017, we made an assessment of the salinization degree of the subaqual landscape on the II terrace of Nero lake. The possibility of hydromorphic solonchaks forming was shown. The factors and conditions of their forming and the relatively sustainable functioning in the humid climate of the southern taiga subzone were examined. The seasonal dynamics of the profile distribution of water-soluble salts, carbonates, gypsum and storage of salts in two soil pits within the impact zone of the salty spring (the former salt industry center) was revealed. To identify the long-term salinization dynamics in the Varnitsy landscape the information on water types from the salty spring, groundwater and soil extraction over a period of a hundred years of sporadic observations was analyzed. The current monitoring data indicated active salinization processes in the landscape and salts migration beyond the soil profile into the associated system of the Nero lake tributaries.