Orders in the soil classification system of Russia: Taxonomic distance as a measure of their adequate identification

Taxonomic distances between pairs of soil orders in the Russian soil classification system have been calculated using a methodology suggested for calculation of taxonomic distances between the Reference Soil Groups in the international soil classification system (WRB). Basing on the data obtained, some proposals for the development of the Russian soil classification system have been formulated. Most of the orders are characterized by considerable taxonomic distances between them, and their identification in the classification system is doubtless. Small taxonomic distances are characteristic of the following pairs of orders: organo-accumulative and structural-metamorphic soils, hydrometamorphic soils and lithozems, and cryometamorphic and eluvial soils. Therefore, criteria for defining some orders, and/or profile formulas for some soil types composing the orders may be revised. The comparison of taxonomic distances between soil orders in the Russian system and between Reference Soil Groups in the international system allows us to suggest their certain similarity.     

Inclusion of soils and soil-like bodies of urban territories into the Russian soil classification system

The results of the Internet discussion on the classification of urban soils aimed at evaluating their possible inclusion into the modern Russian soil classification system adopted by a wide range of specialists are presented. The first step was to address the urban diagnostic horizons as the basis for identifying soil types according to the rules of the Russian soil classification. New diagnostic horizons were proposed for urban soils: urbic (UR), filled compost-mineral (RAT), and filled peat (RT). The combination of these horizons with other diagnostic horizons and layers of technogenic materials correspond to different soil types. At the subtype level, the diagnostic properties (qualifiers) that may reflect both natural phenomena (gley, alkalinity) and technogenic impacts on the soils (urbistratified; phosphatic; or poorly expressed urban—ur, rat, rt) are used. Some corrections were proposed for the system of parent materials in urban environments. Urban soils formerly described in another nomenclature—urbanozems, urbiquasizems, and culturozems—are correlated with the taxa in all the trunks of the system. The proposals accepted can be used for the next updated version of the new Russian soil classification system.     

Verification of the <Emphasis Type="Italic">Classification and Diagnostic system of Russian soils</Emphasis> (2004) on the materials of a collection of soil monoliths from the V.V. Dokuchaev Central Soil Museum

The first in the world collection of soil monoliths from the Dokuchaev Central Soil Museum (St. Petersburg) was examined in order to test and verify the new substantive-genetic classification system of Russian soils. This work made it possible to introduce a number of refinements in the second edition of the Russian soil classification system (2004). These refinements included the addition of new diagnostic horizons and features and the specification of their definitions. The analysis of the museum collection of soils has definite advantages, as it allows one to work with soils from different geographic regions simultaneously, to consider morphological features of soils under standard conditions, to use analytical soil data, and to analyze different names (i.e., interpretations of the genesis) given to the same soils. At the same time, a critical analysis of the collection creates necessary prerequisites for a comparative analysis of soils from different regions of Russia with the national reference soil base, which is important in order to reveal the real pedogenetic diversity and improve the information base on soil resources in Russia.     

Soil temperature regimes in the discontinuous permafrost zone in the east European Russian arctic

Temperature regimes of eleven plots with tundra soils were studied in the northeastern part of European Russia within the discontinuous permafrost zone. The duration of soil temperature records ranged from 1 to 9 years. The selected plots were representative of the diversity of landscape and soil conditions in the study area. Virgin tundra soils, a cultivated soil under sown grassland, and soils of secondary biocenoses that developed in place of the former sown grasslands were studied. It was shown that the winter and mean annual temperatures in the permafrost-affected soils drastically differ from those in the soils without permafrost, though the summer temperatures in the root zone of both soil groups are relatively similar. The soil temperature regimes were classified according to Russian (Dimo, 1972) and American (Soil Taxonomy, 1999) classification systems. The degree of detail provided by the Russian system proved to be somewhat greater; at the same time, in contrast to the American system, it does not make it possible to distinguish the soils with warm permafrost in the discontinuous permafrost zone from the soils without permafrost at all.     

Modern Azerbaijani soil classification system

A new soil classification system is elaborated on the basis of the legend to the soil map of Azerbaijan on a scale of 1: 100 000. The classification system includes above-type categories and a detailed list of anthropogenically transformed soils. It is based on the profile-genetic and evolutionary concepts. The soil classes (the highest taxon) include naturally developed, anthropogenically modified, and technogenically disturbed soils. The lists of soils of the first two classes are similar to those of the new Russian soil classification system, contrary to the class of technogenically disturbed soils, which is subdivided into soil orders with respect to the particular kinds of soil disturbance. The concept of soil types is generally preserved in the new classification. The diagnostics of soil types are based on the sequences of genetic horizons (types of soil profiles). The latter are used for finding proper correlation of the distinguished soil types with analogous soils in the WRB system.     

Suprapermafrost Horizons of the Accumulation of Raw Organic Matter in Tundra Cryozems of Northern Yakutia

In the profiles of cryozems (Oxyaquic Turbic Cryosols) developing in tundra of northern Yakutia under conditions of shallow active layer, suprapermafrost horizons of the accumulation of raw organic matter are formed. Taking into account their genesis, stable and regular position in the soil profile, paragenetic links with the overlying horizons and neighboring soil profiles, and a set of diagnostic features and properties, these horizons can be separated as a new type of genetic soil horizons—the organomineral accumulative suprapermafrost horizon (CRO). Its qualitative composition (the ratio of organic and mineral matter in the material) can be reflected at a lower level. In relation to the separation of the new genetic horizon within the framework of the new Russian soil classification system, a new genetic types of soils—cryozem with suprapermafrost accumulation of raw organic matter (suprapermafrost organo-accumulative cryozem)—can be established. Its diagnostic profile has the following horizonation: (O, AO, T)–CR–CRO–┬C.     

Ecological niches of major soil types in Russia: Geographical aspects of the new Russian soil classification system

The factors of soil formation are not directly taken into account in the new profile-genetic Russian soil classification system; they are not reflected in the names and diagnostics of the soils. At the same time, as well as in many other modern soil classification systems, including the American Soil Taxonomy and the WRB system, the choice of the diagnostic criteria, the establishment of the relationships between them, and the setting of the quantitative boundaries between the soil taxa are based on our perception of soil geneses with due account for the factors of soil formation. In contrast to the ecological-genetic soil classification system of 1977, information on the factors of soil formation in the new system is encoded in the properties of the soil horizons. In some cases, this is insufficient for the definite geographic localization of soils and complicates the practical application of the new classification system. In this context, information on the ecological niches of soil types was included in the field manual on soil correlation-an abridged version of the soil classification system published in 2008—in the form of special tables developed for native and agrogenic soils. The analysis of these tables made it possible to outline certain geographic regularities in the distribution of soil types belonging to the trunk of postlithogenic soils.     

Specific features of the morphology of volcanic soils in the altitudinal zones of Kamchatka

Under conditions of active volcanism, the soils on different geomorphic positions (from high-mountain landscapes to river valleys) are formed under the impact of periodic ashfalls. The exogenous processes affect the redistribution of volcanic ashes by the elements of the relief, so that the soils of different altitudinal zones have their own morphological specificity. It is suggested that two additional types of volcanic soils should be included in the new Russian soil classification: the type of alluvial volcanic soils in the order of volcanic soils and the type of volcanic lithozems in the order of lithozems. These soils can be considered intergrades between volcanic and alluvial soils and between volcanic soils and lithozems, respectively.     

Correlation of Soddy Calcareous Soils on the Soil Map of the Russian Federation (1 : 2.5 M Scale, 1988) and in the Russian Soil Classification System

Eurasian Soil Science - Updating of the Soil Map of the Russian Federation (1 : 2.5 M scale, 1988) is planned on the basis of the new classification system of Russian soils. At the first stage,...     

Approaches to the Classification of Soils of the Accumulative Seashores of Russian Northeast

Eurasian Soil Science - A specific group of diverse marsh soils forming on sea coasts in the permafrost zone is proposed to be included into the Russian soil classification system. These soils are...     

Soil map of the Russian Arctic on a 1 : 1 M scale: Contents and compilation methods

A new soil map of the Russian Arctic on a scale of 1 : 1 M shows the soil cover in the north of Eurasia and on the islands of the Arctic Ocean to the north of 68° N. This map has been developed in a geoinformation system in the vector format with the wide use of remote sensing data. The delineated soil polygons show dominant and accompanying soils and the structure of soil cover patterns with indication of soil associations and soil complexes, the character of parent materials, and the topographic conditions. The map of the soil-geographic zoning of the Russian Arctic developed on the basis of the soil map differs from its earlier analogues in a greater degree of detail. The soil map of the Russian Arctic on a scale of 1 : 1 M displays the most detailed information on the soil cover patterns and can be used for solving various problems related to the exploration and development of this territory. Soil names from the new classification system of Russian soils [10] have been introduced into the legend of the map. New soil information and the use of remote sensing data have made it possible to enlarge the number of soil polygons shown on the map and to correct their boundaries in comparison with previous soil maps of the Russian Arctic.     

Diagnostic Horizons in the Classification System of Russian Soils: Version 2021

Eurasian Soil Science - Updating the classification system of Russian soils as a preliminary procedure to the development of its new version is provided by new data, extensive testing of the system...     

Soils of floodplains in arid regions of Inner Asia (the Zavkhan River,Mongolia)

The environmental conditions of soil formation and the diversity and classification position of soils developing on the Zavkhan River floodplain are considered, and the morphogenetic and agrochemical properties of these soils are characterized. It is shown that the conditions of soil formation on the floodplain of the Zavkhan River are specified by the mountainous topography, the effect of the large Mongol Els sand massif, the character of the alluviation processes, the groundwater level and salinity, and the regime of floods. The position of the floodplain in the system of altitudinal zones largely dictates the character of the soil cover pattern. In terms of the new Russian soil classification system, the soils studied belong to three trunks, four orders, and seven types: stratified humus alluvial soils, light-humus alluvial soils, light-humus quasigley alluvial soils, light-humus stratozems, and solonchaks. The soils of floodplain ecosystems in arid regions are characterized by low fertility. For their efficient use for pasturing and crop growing, the ecologically balanced differentiated application of manure, mineral fertilizers (NPK), and some microelements is required.     

Vertigenesis in soils of the central chernozemic region of Russia

On the basis of soil studies along routes and on key plots, 35 new areas of soils with definite features of vertigenesis have been identified in Belgorod and Voronezh oblasts and in the northern part of Volgograd oblast (in the Don River basin). Earlier, vertic soils were not noted for these areas. In the studied region, their portion in the soil cover is much less than 1%. All the delineated areas of vertic soils are confined to the outcrops of swelling clay materials of different origins (marine, lacustrine, glacial, and colluvial sediments) and ages (Quaternary or Tertiary) that may be found in four landscape positions: (1) in the deep closed depressions within vast flat watersheds; (2) in the bottoms of wide hollows on interfluvial slopes and, sometimes, on steeper slopes of local ravines; (3) in the hydromorphic solonetzic soil complexes, and (4) on step-like interfluvial surfaces with the outcrops of Tertiary clays. Within the studied areas, soils with different degrees of expression (six grades) of vertic properties are present. These soils belong to the type of dark vertic soils proper and to vertic subtypes of different soil types according to the Russian soil classification system; according to the WRB system, they belong to Vertisols proper and to reference soil units with a Vertic prefix in the groups of Chernozems, Phaeozems, and Solonetzes. Statistical data on the morphometric indices of the vertic properties (the depth and thickness of the soil horizons with slickensides, a wedge-shaped structure, and cracks filled with material from the upper horizons) and the depth and thickness of the Vertic horizon are analyzed.     

Automorphic taiga soils of the Sredneobskaya Lowland

The morphology of the profile, some chemical properties, and particle-size distribution of the automorphic soils developed from lacustrine-alluvial loamy-clayey deposits in the Sredneobskaya Lowland are considered. The soils of the West Siberian middle taiga zone remain poorly studied. A comparison of our data with data on podzolic soils in the northeastern part of European Russia and with diagnostic characteristics of the soil type of svetlozems included in the new classification system of Russian soils (2004) allows to argue that the studied soils cannot be classified as podzolic soils; most of them also do not fit the diagnostic criteria of svetlozems. The obtained data on the particle-size distribution in the studied soils do not agree with the concept of the sedimentation zonality in the West Siberian Plain.     

Geographical and genetic aspects of the Red Book of Russian Soils

An overview of soil objects from different regions and of different categories that are listed in the Red Book of Russian Soils is presented. Most of these objects are soils that support the existence of rare plant and animal species; the number of reference and zonal soils is almost equal and sufficient attention has been paid to soils that are used for scientific and training purposes. Semidesert soils are represented best; less focus is given to steppe soils; podzols and podzolic soils of Siberia have been given fairly limited consideration. To describe Russian soils in their real diversity makes it necessary to include new reference (cryozems and svetlozems) and rare (granuzem and cryoaridic) soils in the Red Book.     

SOIL CLASSIFICATION WITH PARTICULAR REFERENCE TO THE SEVENTH APPROXIMATION

The fundamental objective of soil classification is the achievement of an agreed world–wide system of maximum usefulness to the widest possible range of users. Such a classification should be natural rather than artificial because soils are natural bodies. Further, it should be hierarchical rather than co–ordinate because hierarchies are readily comprehensible and memorable, can be constructed on the basis of a few characters, and do not need to give equal weight to all criteria used in classifying soils. They also have the advantage of closely denned, mutually exclusive classes which can still make allowance for occasional aberrant profiles or pedons. The historical development of soil classifications is discussed with particular reference to the Russian and French and especially the U.S. Dept. Agric. 7th Approximation. The latter is defended against the main criticisms that have been levelled against it. It is maintained that it has been desired by sound inductive as well as deductive reasoning, that it treats soils as polythetic individuals, that it considers pedons three–dimensionally and that it permits non–hierarchical sub–classifications. Attention is given to the more practical criticisms that there is an undue emphasis on soil moisture and temperature regimes, unknown genetic criteria and the shallower horizons, and that it handles ses-quioxidic soils inadequately. Positive advocacy is made on the ground that the 7th Approximation will facilitate and speed soil research especially in developing countries.     

Correction of a large-scale soil map with the use of the new classification system of Russian soils

A large-scale soil map of one of the farms in the south of Karelia has been analyzed. This map was initially compiled in 1979 on the basis of the official Classification and Diagnostics of Soils of the Soviet Union (1977). We have corrected it with the use of the new Classification and Diagnostics of Russian Soils. Both the names of the map units and the particular delineations on the map have been changed. These changes are related to differences in the principles of soil diagnostics in the old and new classification systems and to real changes in the soil cover that have taken place after the map’s compilation. In particular, large areas of peat bogs have been drained, and the cultivated peat soils have been subjected to accelerated mineralization. Surface planing works after digging drainage channels have also changed the soil cover pattern. The revised large-scale soil map developed on the basis of the new classification system gives more adequate information about the real soil cover.     

中国土壤分类四十年

建国以来土壤分类是不断完善的过程。涉及全国的土壤分类系统至少有9个。可分为三个时期。解放初，采用美国马伯特土壤分类系统，以土类为基本单元，土系为基层单元，其中就有我国特有的山东棕壤、砂姜黑土和水稻土等类型；从1954年开始采用土壤发生分类系统，之后陆续提出了一些新土类，如黄棕壤、黑土、白浆土、砖红壤性红壤等，接着由于对耕地土壤的普查，充实了水稻土、明确了潮土、灌淤土和塍土等的独立土类地位。并提出了其他许多磷质石灰土等新土类。目前正在开始以诊断层如诊断特性为基础、结合我国丰富土壤类型的实际，在已有基础上，建立具有我国特色、具有空量指标的土壤系统分类。但这需要有一个较长的研究和完善过程。