International soil classification system—World Reference Base for Soil Resources—has been published every eight years since 1998, and in each version the number, content, and status of qualifiers was changing. According to the WRB principles, qualifiers, both Principal and Supplementary, reflect soil-forming processes. Analysis of all qualifiers (281) in the latest version of 2022 showed the priority of diagnostic horizons as criteria for identifying both categories of qualifiers, as well as of chemical soil properties. Among anthropogenic qualifiers, technogenic ones are more numerous and diverse. The number of qualifiers is maximum in soils, scattered over the world (Technosols, Cambisols, Gleysols) and minimum in strictly geographically localized soils (Nitisols). Based on their relation to soils, qualifiers are subdivided into universal, identified in almost any soil (by texture, or gley properties), and unique, characteristic of individual soils. The function of the Principal qualifiers is to create a central image of the Reference Soil Group; however, their number can be excessive. Most similar in terms of the set of Principal qualifiers were the pairs of Reference groups: Stagnosols and Planosols, Calcisol and Gypsisol, Alisols and Acrisols, which is due to the similarity of the processes that form them. The Reference groups Histosols and Gleysols are characterized by the most unique set of Principal qualifiers. In constructing the names of qualifiers, in addition to Latin and Greek morphems, formative elements from 26 world languages were involved. As an example of approaches to the analysis of qualifiers, the Podzols Reference Soil Group is considered.

Soil mapping of urban areas is required for solving many applied problems. However, its methodology is still under development. The lack of information about urban soils and the inconsistence of their classifications are the main difficulties, as well as the intricate soil cover patterns in cities and towns. The research was aimed to compile the soil map for the drainage basin of the small urban river Setun at a scale that could reflect its soil cover heterogeneity. Some new approaches to the differentiation of urban and semi-urban soils in accordance with recent ideas on their systematic and land use variants have been proposed. The concept of pedo-urbo-mosaics, which implements the soil cover pattern theory in relation to urbanized territory, has been used for delineating mapping units. The compilation methodology involved the use of open spatial data and GIS technologies. The subdivision of the basin into mapping units was performed using ©OpenStreetMap data and Yandex Maps Web mapping service. Spatial analysis in GIS allowed for mapping the territory with a moderate urbanization rate on a large scale, obtaining a more adequate and detailed spatial representation of the area than in the case of applying the traditional approach. The map, at a scale of 1:60,000 contains 16 natural/semi-natural soils and technogenic superficial formations, as well as 11 pedo-urbo-mosaics. The study may be of methodological interest as an experience in soil mapping of urbanized areas using GIS.

Meadow podbels (dark-humus gleyic and gleyed podbels in the Russian soil classification system) in the west of their range experience deep and prolonged freezing manifested in cryogenic deformations of horizons and in their microstructures. Microfeatures of soils on permafrost are well known, and the objective of this study was to identify them in three profiles of meadow podbels taking into account particular features of their cryological and moisture regimes. Unlike northern permafrost-affected soils, meadow podbels have dark-humus horizons with weakly expressed cryogenic features; in eluvial horizons, these are platy microstructures and numerous humus-iron nodules of different size. In the textural horizons, there are specific microstructures: rounded or ellipsoidal aggregates with humus-iron nodules in the center and ooidal aggregates with iron impregnation in the center and optically oriented clay along the periphery. Typical microfeatures of gley in the lower clayey horizons are combined with partially deformed illuviation clay coatings. Unlike soils with permafrost, the separation of micromass and skeleton grains is weak, as well as their ring-shaped orientation.

Podzolic-brown forest soils on the Soil Map of Russian Federation, scale 1 : 2.5 M, are widespread on the plains and plateaus of the Far East, referred to the Eastern brown-forest-soil area in the scheme of soil-geographical zoning. There, in Primorye and Priamurye regions, they are confined to various parent rocks and to different climatic and biota conditions. In the Classification of Soils of Russia (2004, 2008), there are no direct analogues of podzolic-brown soils in the map legend. To name these soils in the Russian classification system, regional publications (N.A. Kreida, G.I. Ivanov, V.I. Roslikova et al., N.M. Kostenkov, E.A. Zharikova) were reviewed: morphological and physicochemical properties of podzolic-brown soils were assessed in terms of their compliance with the diagnostic criteria of their possible analogues in the Russian system. The comparison has shown that in Primorye, on stony-loamy-clayey derivates of hard rocks, podzolic-brown soils correspond to soddy-pale-eluvial-metamorphic soils with textural differentiation, on loamy-clayey lacustrine-alluvial and colluvial deposits – as dark-humus podbels. In the north, in Priamurye region, podzolic-brown gley soils have properties of both texture-differentiated soils with the BT diagnostic horizon and of soils with a specific cryogenic structure in the middle cryometamorphic horizon. In the ideology and nomenclature of the Russian classification system, the former are defined as mucky-podzolic gleyic soils, the latter soils, as depending on the intensity of surface gley and structure development, can be defined as cryometamorphic podzolized gleyzems, eluvial-metamorphic cryometamorphic gleyic soils, or gleyic svetlozems.

In 2024, the journal Pochvovedenie—the first journal in the world entirely devoted to soil sciences—celebrated its 125th anniversary. Pochvovedenie is a unique periodical based on the fundamental ideas of genetic soil science created by the Russian scientist V.V. Dokuchaev. The article briefly describes the history of the journal and the stages of its development. It reveals the main topics and directions that have developed in the journal over the past 5–10 years and provides examples of the most interesting cited publications during this time. It shows that the journal is developing dynamically and harmoniously under current conditions.

The soil cover of cities and towns within their administrative boundaries is composed of soils, more or less modified by the urban environment along with native, agricultural soils and non-soils. For preserving this diversity when introducing these new objects to the unified digital model of the soil cover of Russia, soil maps of 10 “test” cities have been compiled. The cities are located in several natural zones, and are intermediate in terms of their population. Mapping was performed by means of detailed purposeful deciphering, data on mapping units on the original soil map, and recent systematics of urban soils and their dependence on the urban environment. The approaches applied were supported by the experience in soil mapping of St-Petersburg, Moscow, Volgograd and few other cities. Soils were qualified in the system of Russian soil classification, and their areas, along with those of non-soils, were regarded as units in the theory of soil cover patterns. In all cities investigated, soil associations comprised urban soils per se, transitional soils including agro-soils and conventionally native ones; their ratios in the soil cover depend on both historical-socio-economical reasons and the natural enviroment.

Natural reforestation on abandoned arable lands is one of the characteristic processes that trigger the transformation of soil organic matter accompanied by changes in the abundance, biomass, and taxonomic structure of soil macrofauna. The assessment of the time for a potential return of soil properties and macrofauna to their natural state, dynamics of soil organic matter stocks, and the role of macrofauna in this process at different stages of postagrogenic successions is relevant in the context of predicting the changes in ecosystem components and their role in organic carbon sequestration under various land use scenarios. The stock of organic carbon, soil morphological properties, as well as the abundance, biomass, and taxonomic structure of soil macrofauna in arable lands of five stages of pine forest restoration (fallow meadows and pine forests of different ages), and primary forests in the Smolenskoye Poozerye (Smolensk Lakeland) National Park (Smolensk oblast, Russia) have been examined. The soils of 85–100-year-old pine forests retain the lower boundary of the former humus horizon; at the meadow stage, restoration signs appear, namely, a shallow humus horizon pierced with roots and later transformed into a raw-humus horizon in young forests. By the age of 80, the carbon stock in the mineral soil part restores to almost background values. The soil macrofauna composition radically changes with the substitution of meadow communities by forest ones. At the initial stages (in agrocenoses and fallow meadows), the macrofauna of organomineral soil horizons is prevalent, being represented by soil earthworms and larvae of scarab beetles. Further, the macrofauna of organic horizons is restored to contain a high share of saprophages, such as epigeic and epi-endogeic earthworms, which contribute to the differentiation of litter into subhorizons. The biomass of saprophages negatively correlates with the carbon stock in the mineral part of forest soils, its content in the litter, and litter thickness and positively correlates with the share of easily decomposable litter fraction.

Usually, soils changed by farming (agrogenic soils) are not shown on small-scale maps, the Soil Map of the Russian Federation, 1 : 2.5 M scale (1988), in particular. One of the issues of the map updating performed in the Dokuchaev Soil Science Institute is the introduction of agrogenic soils into the map contents and representation of some of the former native soils as agrogenic soils on the updated map. Preliminarily, all native soils shown on the map have been reclassified into the new Russian soil classification system. Agrogenic soils in this system are separated as agro-soils in different orders and form a specific order of agrozems. Agrogenic soils have been identified in the soil polygons in agreement with the map showing the percentage of arable land in Russia as determined by I.Yu. Savin with coauthors (2020) and linked to the polygons of the soil map. We have identified the classification position of the initial native soils involved in arable farming. Overall, 114 legend units representing agro-soils and agrozems have been identified. This number is dictated by the diversity of native soils subjected to the agricultural impact producing their agrogenic modifications. Agrogenic soils on the updated map are shown in 4813 polygons out of the total of 25 711 polygons. Chernozems are characterized by the greatest diversity of agro-soils and the largest number of polygons containing diverse agro-chernozems. The order of texture-differentiated soils is also rich in agrogenic soils, both agro-soils and agrozems. Arable soils initially belonging to the order of Al–Fe-humus soils are present in a relatively small number of polygons and are represented only by Al–Fe-humus agrozems. The number of polygons with participation of agrogenic soils and their proportion in the soil cover illustrates the geographical pattern of their distribution, in particular, homogenous or mosaic patterns in the areas of different soil orders.

The largest area of taiga gley-differentiated soils on the Soil map of Russian Federation, scale 1:2.5 M, is located in the north of West Siberia. Small areas are dispersed over the northwestern European Russia, Eastern Siberia and the North-East. Interpretation of taiga gley-differentiated soils in terms of Russian soil classification system (2004) is rather ambiguous owing to high diversity of ecological conditions where these soils occur, аs well as variability of soil morphological, chemical, and physicochemical properties in diverse mapping units. Comparing properties of taiga gley-differentiated soils described in the Program of the map (1972) and in regional publications with the diagnostic criteria for soil types in some orders of the Russian classification system made it possible to find adequate names and taxonomic position for these soils. Thus, taiga gley-differentiated soils in the middle and northern taiga of Western Siberia proved to be allocated to several orders: weakly differentiated and gleyed soils with a brown profile were referred to the order of organo-accumulative soils as shallow-peat gleyic soils; their more hydromorphic variants – taiga gley-differentiated shallow-peat soils were defined in the order of gleyzems, as peat gleyzems, soil with morphologically differentiated profile having a particular cryogenic structure were qualified for svetlozems and iron-illuvial gleyic svetlozems in the order of cryometamorpic soils, and for eluvial-metamorphic soils of the same order in case of cryogenic structure was absent. Taiga gley-differentiated soils in their northwestern area are confined to varved clays and correspond to (soddy-)eluvial-metamorphic gleyic soils.

The content, legends and methods of designing the basic soil maps in complex regional atlases published over the past 60 years were analyzed. The atlases were grouped in accordance with the time of publication and potential users. The main attention was paid to the content and conceptual background of maps, their compliance with the rules and experience of traditional soil mapping in Russia, as well as to the requirements for soil maps, i. e. completeness of information with new knowledge included, visual clarity and readability. The content of maps is assessed in the following aspects: natural soils, presence of human-modified soils, classification used, soil cover composition and pattern, relief, and soil texture. The legends were evaluated in terms of information on soils and presentation of the mapping concepts, namely, legend structure, the number of units and the order of soils in the legend; methods of cartographic presentation were discussed as well. Soil maps in the atlases dating from the second half of the last century were compiled in accordance with the zonality concept; the soils basically corresponded to the USSR soil classification (1977) with some additions. In the atlases of the latest period, there are several maps compiled according to the new classification of soils in Russia. Soil maps in the atlases mostly used standard cartographic techniques; at present a certain deviation from the rules and standards of traditional soil cartography is obvious, which affects the information content and visual clarity of maps

Natural reforestation on the abandoned arable lands is one of the characteristic processes that triggers the transformation of soils, accompanied by the change in the abundance, biomass, and taxonomic structure of the soil macrofauna. The assessment of the restoration potential of the soil properties and soil macrofauna to the natural state, the duration of this period, the dynamics of soil organic carbon stocks, and the role of macrofauna in this process at different stages of post-agrogenic successions is relevant for prediction of changes in ecosystem components and their role in the storage of organic carbon under various land use scenarios. The work is based on the data on organic carbon reserves, morphological properties of soils, abundance, biomass and taxonomic structure of the soil macrofauna of arable lands, primary forests and 5 stages of pine forest restoration (fallow meadows and pine forests of different ages) at the Smolenskoye Poozerye National Park (Smolensk region). It was revealed that in the soils of the 85–100-year-old pine forests, signs of plowing are preserved in the form of the smooth lower boundary of the humus horizon. At the same time, signs of soil regradation appear already at the meadow stage and are expressed in the formation of a thin humus horizon penetrated by roots, which transforms further at the next stages. In the litter and mineral part of the soil, the carbon stocks change non-monotonically with a maximum at the meadow stage and a minimum in 70–80-year-old forests. By the age of 80, the stock of organic carbon in the mineral part of soils is almost restored to the background values. The composition of soil macrofauna changes drastically during the transition from meadow to forest communities. At the initial stages (in agrocenoses and fallow meadows), the fauna of mineral soil horizons predominates: endogeic earthworms and larvae of lamellar beetles. Further, the fauna of organic horizons is restored, among which there is a high proportion of saprophages – epigeic and epi-endogeic earthworms, which contribute to the differentiation of litter. The biomass of saprophages has a negative correlation with the carbon reserves in the mineral part of forest soils, the thickness and reserves of organic carbon in the litter, and a positive correlation with the share of the easily decomposable litter fraction.

In the USSR and in Russia, women predominated among soil scientists despite the problems related to field research in tundra, taiga, mountains and other severe environments. One such woman was Maria Glazovskaya, who worked in highlands and semi-deserts studying little known soils, both recent and relict, primary pedogenesis, and geochemical features of hard rock weathering. Her scientific interests were diverse, and corresponded well with the social and scientific trends of the moment. She put forward new ideas and applied existing ones in several spheres of soil geography and landscape geochemistry. She proposed new approaches for compiling soil and landscape-geochemical maps, including using soil properties to predict the risks of soil pollution with heavy metals, and using landscape-geochemical methods to prospect for economic minerals. In the interdisciplinary conceptual sphere, Glazovskaya tried to bring together soil science and landscape geochemistry, and included these two subjects in the name of the department in Moscow University that she headed for more than 30 years. She was a scientist always looking for her own way in the interdisciplinary world of earth science.

Cryoaridic soils were proposed to be identified as an individual genetic soil type by Vladimir Volkovintser in the 1970s. Volkovintser argued that the specific properties of these soils are in good agreement with the soil-forming factors: ultracontinental climate, cryoxerophytic steppe or tundra-steppe vegetation, dry permafrost, and skeletal parent material. In cryoaridic soils, the properties of chestnut and pale soils are combined, but their individual features are due to the specific cryohumus AK horizon and secondary carbonates dominated by pendants. Cryoaridic soils were not included in the soviet soil classification system of 1977; in the Russian soil classification system, the type of cryoaridic soils with the AK–BPL–BCA–Cca horizons is included in the order of pale-metamorphic soils with the pale-metamorphic BPL horizon as diagnostic for all soil types of this order. However, our field research, analysis of publications, and the study of soil in the Central Soil Museum give us grounds to verify diagnostic criteria, to change the profile type formula of cryoaridic soils, and to review their taxonomic position in the classification system. We argue that the BPL diagnostic horizon should be replaced by the diagnostic property (pl), which means that cryoaridic soils should be transferred into another order, presumably, the order of humus carbonate-accumulative soils. Some additional subtypes are proposed. On highly skeletal shallow parent materials, cryohumus soils belonging to the order of organo-accumulative soils are developed.

The dark-humus soil type was included in the updated legend of the Soil Map of the Russian Federation at scale 1 : 2.5 M, converted to the system of Soil Classification of Russia. The soil profile starts with the dark-humus horizon gradually merging to the parent rock; any mid-profile diagnostic horizons are absent. Large areas of dark-humus soils are found in the forest-steppe, steppe and taiga zones of the European Russia, Western and Central Siberia, in the Trans-Baikal region, the Altai-Sayany Mountains, and the Caucasus. The type of dark-humus soils comprises both mesomorphic soils (of normal moisture conditions) and soils with additional surface or ground-water moisture. The main prerequisites for the formation of dark-humus soils are, on the one hand, the climatic conditions favorable for the dark-humus horizon formation, and, on the other hand, parent material - mostly derivates of hard rocks, restricting the development of mid-profile diagnostic horizons. In the updated map, the following initial legend units are partially or completely converted to dark-humus soils: several units of chernozems, dark-gray forest and gray forest non-podzolized soils, soddy-taiga base-saturated and slightly unsaturated soils, several mountain soils, a significant part of soddy-calcareous soils, as well as some mountainous forest-meadow soils. The diversity of dark-humus soils subtypes is determined by secondary carbonate features, weak signs of clay accumulation and podzolization, alteration of the mineral mass, gley and cryogenic phenomena.

As part of updating the classification system of soils of Russia, analysis and revision were performed for its three diagnostic elements – horizons, properties and materials – as they are in the versions of 2004 and 2008: Classification and Diagnostic System of Russian Soils and Field Guide for Identification of Russian Soils. Our paper on the proposed changes in the composition, definitions, and indexing of diagnostic horizons was published in this journal earlier (vol. 54, no. 8, 2021), and this paper on diagnostic properties is its continuation. Unlike the descriptions of horizons, the scheme for describing diagnostic properties (qualifiers) has been preserved, although some criteria for their identification have been clarified, 20 new qualifiers have been introduced; some definitions and symbols have been improved. New was the approach to diagnostic properties-qualifiers in terms of their taxonomic functions: they were specified for the levels of subtype and genus. The open character of the system allows the expansion of the number of qualifiers if required, as well as the removal of restrictions on their confinement to certain soil types, which was one of the frequent suggestions of users. It is proposed to introduce a special section in the classification system: “Soil-forming rocks and substrates,” to formulate brief definitions of each one there, and to introduce human-affected and artificial materials. As in the case of diagnostic horizons, the proposals are based on extensive materials—field data, publications, discussion with colleagues, and addressing to the international soil classification. An updated list of qualifiers is attached.

The development of the digital model of the soil map of Russia derived of the map of the Soviet Russian Federation, 1988, compiled in Dokuchaev Soil Science Institute, comprises the transfer of soil names in the initial legend to those in the new classification system of Russian soils (2004). Floodplain soils (only native) are represented by seven legend units (out of 205) that were named in terms of soil classification of USSR, 1977, and part of their names indicated ‘landscapes’ rather than soils, which disagrees with the principles of the new classification system. Basing on numerous publications and following the rules of the new system, soils were renamed. Most of them were referred to alluvial soil types within the synlithogenic trunk (Fluvisols), and their new names indicate both their properties and their zonal attachment. In order to obtain more adequate patterns of soils in river valleys additional soils were introduced including stratified-alluvial soils in the trunk of primary pedogenesis (Regosols). Simultaneously, the composition of polygons in the database was revised in accordance with regional data; human-modified soils were introduced (agro-soils and urbo-soils).

The development of the digital model of the soil map of Russia derived of the map of the Soviet Russian Federation, 1988, compiled in Dokuchaev Soil Science Institute, comprises the transfer of soil names in the initial legend to those in the new classification system of Russian soils (2004). Floodplain soils (only native) are represented by seven legend units (out of 205) that were named in terms of soil classification of USSR, 1977, and part of their names indicated ‘landscapes’ rather than soils, which disagrees with the principles of the new classification system. Basing on numerous publications and following the rules of the new system, soils were renamed. Most of them were referred to alluvial soil types within the synlithogenic trunk (Fluvisols), and their new names indicate both their properties and their zonal attachment. In order to obtain more adequate patterns of soils in river valleys additional soils were introduced including stratified-alluvial soils in the trunk of primary pedogenesis (Regosols). Simultaneously, the composition of polygons in the database was revised in accordance with regional data; human-modified soils were introduced (agro-soils and urbo-soils).

Cambisols – soils in the WRB system with a broad range of properties and occurring in diverse environments – have been chosen as an example for interpretation of soil units on the updated version of the Soil Map of the Russian Federation (1988), which is essential for communicating soil knowledge. We have compared three soil maps with legends in the FAO or WRB system with the updated soil map of Russia to identify areas corresponding to Cambisols; we analyzed definitions and diagnostics of Cambisols in the FAO/WRB system in its historical development and compared them with diagnostics of soil units on the updated soil map of Russia. Soils of three metamorphic orders in the new Russian classification generally correspond to the definition of Cambisols with the best coincidence for burozems (Dystric or Eutric Cambisols) and less complete coincidence for rzhavozems and cryometamorphic soils; identification of Yakutian pale soils in the WRB system is rather ambiguous. The scale of the Russian map (1 : 2.5 M) and rather detailed soil names in the legend require more complete WRB soil names; for this purpose, several principal and supplementary qualifiers may be used, or even new ones may be borrowed from other reference groups.