ИСТИНА

The whole complex of soil properties forming in the long process of evolution is used in soil diagnostics. The different situation is for the urban and human-made soils. We study constructed Technosols, Technosols on fresh sediments and the Technosols gradually forming in the urban environment for a long time. There are no diagnostic horizons for the Technosols Reference Group in WRB for soil resources. The substrate approach have been applied. So only such properties like amount and source of artifacts or existing of impermeable layers are used. There is also a genetic approach (Prokofeva, Gerasimova, Besuglova, etc., 2014), which proposes the distinction of a special synlitogenic diagnostic horizon, marking the stages of specific urban synlitogenic soil formation in the thickness of the urban man-made deposits. Using this approach, we face the problem of separating real soil horizons from layers of human-made deposits as both contain significant amounts of artifacts. Their chemical and physical-chemical properties are also similar, as they correspond to the general geochemical characteristics of the urban environment. Morphological description of soils, determination of soil density, filtration coefficient, soil hardness were carried out. Examining the soils of Moscow and other Russian cities, we found that pedogenetic horizons differ from layers of man-made deposits in physical properties. The layer of man-made deposits on which the constructed Technosols are created can retain negative physical properties for many years. The studies was supported by Russin Foundation for Basic Research, Project № 19-29-05252.