Dynamics of physical properties of soils and humus reserves in salted soils under desertification

Abstract

The dynamics of the physical properties and reserves of humus in saline soils of an arid semi-desert zone is presented. The basis for the research was observational data for 2010-2022. in a typical hilly landscape of the Astrakhan region. A grid of 100 × 100 m was laid. Soil studies were carried out at the grid nodes along the sampling layers. We studied the change in physical properties (soil moisture; salt content according to the amount of dense residue; soil density; filtration coefficient; soil porosity; moisture reserve), humus reserves and salt state of saline soils under desertification. Comparative analysis showed that negative changes have taken place in the study area and it can be stated that the processes of soil degradation and desertification are intensively developing. It has been established that in the soil layer of 0–40 cm there was a significant reduction in soil moisture reserves against the background of an increase in maximum air and soil surface temperatures, as well as changes in the hydrological regime because of the embankment of the territory. Dehumification processes are observed. The most clearly negative trend was revealed for meadow solonchaks. The change in the hydrological regime of the territory because of embankment contributes to an increase in the areas of automorphic soils in the landscape and a reduction in the areas of meadow soils. An increase in the degree of salinity and compaction was recorded for automorphic zonal soils. The physical destruction of the Baer's hills exacerbates the processes of degradation and the development of desertification in such conditions.