Meadow soils on the Soil map of Russian Federation at a scale of 1 : 2.5 million in the system of soil classification of Russia

The legend of the Soil Map of the RSFSR at a scale of 1 : 2.5 million (SMRF) presents five units of meadow soils. Their small areas are located in many regions of Russia. The search for correlations between the meadow soils of the original legend of the SMRF and soils in the Classification System of Russian Soils (CSRS) was carried out on the basis of a comparative analysis of soil-forming factors, morphological and analytical characteristics of meadow soil profiles in publications, where soil pit locations coincide with their areas on the map. According to publications, the meadow differentiated soils of the Khanka-Ussuri and Middle-Amur Plains correspond to five different soils that differ in soil formation conditions, properties and classification position (Ivanov, 1976). Thus, meadow-brown bleached (meadow podbels podzolyzed according to the classification of soils of the USSR) and meadow-gley bleached soils of the Khanka-Ussuri Plain correspond in the CSRS to dark-humus gleyic cryometamorphosed podbels and dark-humus humus-cryometamorphosed gley podbels. Meadow-gley podzolyzed and meadow-gley solodiс soils, formed under hydromorphic conditions on the young terraces of the Khanka-Ussuri Plain, correlate in the CSRS with humus-soddy-gley podzolyzed and dark-humus-gley solodiс carbonate-segregationary soils. Meadow-brown gley-bleached soils (meadow podzolyzed-gley soils according to the USSR soil classification system, 1977) of the Middle-Amur Plain, proposed in the CSRS (2008) as analogues of dark-humus-gley podzolyzed soils, can be defined as mucky-humus-gley podzolyzed dark-tonguic soils based on a combination of diagnostic properties. Meadow undifferentiated soils of the SMRF legend belong to two orders of the CSRS: organo-accumulative and gley soils. Their humus horizons are diverse: dark-humus, mucky-dark-humus (AUh), soddy (AY), mucky-humus (AH). Soils of large alases of Yakutia are characterized by unique carbonate peat-dark-humus upper horizons, they have also gleyic and solonetzic features, sometimes salinity in the profile.