FEATURES OF FORMATION, COMPOSITION, AND PROPERTIES OF THE ALLUVIAL SOILS OF THE COASTAL LANDSCAPES OF THE LOWER DON REGION

The results of the expedition of 2022 to study the coastal landscapes of the Lower Don are presented. By the method of ecological-geographical profiling 4 types of soils with different morphological as well as physical and chemical properties of alluvial soils have been studied. The soil cover of the key sites is represented by alluvial soils with different layers depth of the river alluvium and textural differentiation by granulometric composition. The upper horizons are turfy, the profile is stained with humus, in the middle part the horizons are of heavy loam granulometric composition with signs of fusion and salinization, in the underlying ones there are rusty-ochre spots of iron and blue spots of gley. Soil-forming sediments are alluvial deposits of different granulometric composition. Physical and chemical indices of soils characterize formation of alluvial soils of different degree of salinity, granulometric composition, density, etc. It has been noted that the upper layers are often non-saline and poorly compacted, while the underlying ones are slightly and medium saline, have heavy loam and clayey granulometric composition. In terms of pH, the upper horizons are neutral, while the underlying ones are weakly and moderately alkaline, which is due to the development of salinization processes in them. Expeditionary and cameral works have established that at present in the alluvial soils of the Lower Don a redistribution as well as changes in the structure of sandy alluvium along the soil profile occurs, so in the structure of the soil cover meadow and meadow-alluvial soils of large watercourses are transformed into low thickness alluvial layered soils, formed on floodplain and old sands, as a result of siltation and redistribution of solid sediment flows.

Lower Don, coastal landscapes, alluvial soils, morphological properties, physical and chemical properties, soil formation processes