Comparison of the results of soil profiles’ diagnostics performed in three classification systems

Three soil classification systems—the World Reference Base for Soil Resources (WRB), Soil Taxonomy, and the recent Russian system—were used for the identification of 17 soil profiles in southwestern Poland; all the systems put emphasis on the soil properties as diagnostic criteria. Different soils developed on glaciofluvial plains, loessic uplands, and in the Sudetes Mountains were classified. The best correlation between the classification decisions in the different systems was obtained for the most widespread soils owing to the similarity of the diagnostic criteria, which were essentially close although not coinciding. The most prominent divergence between the systems in both the names and the taxonomic categories of the soils was found for the polygenetic soils and for the soils developing from the lithologically discontinuous parent materials. It was also found that the diagnostic elements differ in terms of their taxonomic importance among the classification systems.     

World Reference Base for Soil Resources—Its fourth edition and its history

The fourth edition of the international soil classification system World Reference Base for Soil Resources (WRB) was released in 2022. It maintains the 32 Reference Soil Groups at the first classification level. Most qualifiers (second level) and most diagnostic horizons, properties and materials were maintained but some were abolished and new ones introduced. The main part of the fourth edition is followed by six annexes, most of them are new. For the first time, the WRB has a Field Guide (Annex 1) to facilitate field survey and to assure that all field characteristics required in the classification are reported. The fourth edition also provides designations for horizons and layers (Annex 3), which was not the case in the second and the third edition. The wordings of the definitions were harmonized, and the same features are worded in the same way throughout the text (including the annexes). Ambiguities have been corrected and many definitions written in a more concise and a more didactical way. The WRB has a long history. Four editions have been published: 1998, 2006 (with update 2007), 2014 (with update 2015) and 2022. Editor is the Working Group WRB of the International Union of Soil Sciences. The WRB followed the Legend and the Revised Legend of the Soil Map of the World. This map was edited by FAO (Food and Agriculture Organization of the United Nations) and UNESCO, and the system is known as the FAO Soil Classification System. In addition, WRB incorporated ideas from the former Working Group International Reference Base for Soil Classification that existed from 1982 to 1994.     

天山中部北麓丘陵地带土壤发生特性与系统分类

通过样地调查与土壤理化性质分析相结合对天山中部北麓丘陵地带的土壤特性进行研究,确定各剖面的诊断层和诊断特性及其在系统分类中的位置。结果表明天山中部北麓丘陵地带在系统分类中可划归为3个土纲4个土类;系统分类中土壤的分类位置与发生分类位置并不具有简单的一一对应的关系。     

冀北地区盐碱化土壤系统分类的归属研究

采用《中国土壤系统分类（第三版）》和《中国土壤系统分类——土族与土系建立原则与标准（试用稿）》对冀北地区7个盐碱化土样进行了分类,共划分了4个土纲,6个亚纲,6个土类,7个亚类,建立了平地脑包系等7个土系。研究结果表明,系统分类亚类与发生分类亚类参比并无对应关系;部分盐碱化土壤并未在系统分类高级单元中体现盐碱特征,而在基层分类中对盐分含量和积累位置进行补充,表明系统分类的划分指标要求更严格,分类更标准。最后讨论了盐碱化土壤诊断层、诊断特性和土壤分析方法的确定等问题。     

On the development of soil-genetic zoning

The principles of typological soil-genetic zoning based on the substantive-genetic classification of Russian soils (2004) and realized for the State Soil Map of Russia on a scale of 1 : 1 M are considered. Three categories of characteristics are applied to the system of zoning units: taxonomic, process-based, and landscape- indicative characteristics. The relationship between them changes in dependence on the taxonomic level of the zoning unit; at the lower level, the spatial (landscape-indicative) criterion plays the major role. This criterion is also important in the delimitation of soil groups (soil communities) serving as the central taxonomic unit of the zoning. At this level, all the three groups of characteristics are equally important. The definitions of the taxonomic units of the soil-genetic zoning are given, and their characteristic features are described. An algorithm of the zoning procedure is illustrated by the example of the maps developed for the Privolzhskii federal okrug. It is suggested that the soil-genetic zoning can be used as one of the ways to update the State Soil Map.     

Development of Soil Taxonomy in the United States of America

Soil Taxonomy was developed primarily for the practical purpose of supporting the National Cooperative Soil Survey Program in the United States. The previous system of classification was limited in its usefulness and could not be applied consistently by a large cadre of soil scientists with diverse levels of skill and experience. The first edition of Soil Taxonomy, published in 1975, was developed under the leadership of Dr. Guy Smith over a period of about 25 years. The magnitude and complexity of the information favored the use of a hierarchical system presented as a key for consistent application. Operational definitions were used to identify taxonomic limits and diagnostic horizons and features, so that each taxon conveyed the same meaning to every user. The application of Soil Taxonomy had several important impacts on the soil survey program in the United States. The emphasis on objective, measurable diagnostic horizons and features to define classes made all competent soil scientists, regardless of experience and rank, equally capable of accurately and consistently classifying soils. The use of quantitative class differentia improved the quantity and quality of the field data collection. The property ranges of soil series and their geographic distribution have generally been narrowed over time, thus, allowing more precise interpretations to be made. Soil Taxonomy has benefited the soil correlation process by grouping the nearly 22 000 series currently established in the United States in ways that allow us to efficiently compare and differentiate competing soil series and coordinates their use among survey areas. After publication in 1975, Soil Taxonomy was further refined through the work of nine international committees and many individuals. This work culminated in the publication of the second edition in 1999 and, most recently, the 9th edition of the Keys to Soil Taxonomy in 2003. Today, two international committees are considering revisions to the moisture and temperature regimes and improvements to the classification of anthropogenic soils. Published in Russian in Pochvovedenie, 2006, No. 2, pp. 161–167. This article was submitted by the authors in English.     

Urban Soils: Diagnostics and Taxonomic Position according to Materials of Scientific Excursion in Moscow at the Suitma-9 Workshop

Using the latest version of the international soil classification (WRB 2014/2015) and the classification of soils of Russia (2004/2008), the authors attempted to demonstrate how specific profiles of urban soils in green massifs are classified at different taxonomic levels. The soil profiles were shown in the excursions of the 9th International Conference “Soils of Urban, Industrial, Traffic, Mining and Military Areas” and were discussed by the representatives of national scientific schools. The diversity of the soils studied is determined primarily by the technology of their creation or by the nature of human impact, soil age, properties of the soil-forming rock, and, to a lesser extent, by the type of artificial phytocenosis. By the properties of their profiles, soils are qualified as ones on technogenic deposits (artificial buildings or displaced natural grounds with fragments of soil horizons), buried agrozems and cultural layers. The comparison of two classification systems showed their similarity with respect to the taxonomic level. One can note a similarity of the main solution: are the soils natural or anthropogenic, although the degrees of “anthropogeneity” given in their names may not coincide. The existing differences in the sets of characteristics–qualifiers reflect the genetic trend in the Russian soil classification and strict following the rules in the WRB system.     

Classification of Ferrallitc Soils in Chinese Soil Taxonomy

The development of the classification of ferrallitic soils in China is reviewed and the classification of Ferralisols and Ferrisols in Chinese Soil Taxonomy is introduced in order to discuss the correlation between the ferrallitic soil classification in the Chinese Soil Taxonomy and those of the other soil classification systems.In the former soil classification systems of China,the ferrallitic soils were classified into the soil groups of Latosols,Latosoilc red soils,Red soils,Yellow soils and Dry red soils,according to the combination of soilforming conditions,soil-forming processes,Soil features and soil properties.In the Chinese Soil Taxonomy,most of ferrallitic soils are classified into the soil orders of Ferralisols and Ferrisols based on the diagnostic horizons and /or diagnostic characteristics with quantitatively defined properties.Ferralisols are the soils that have ferralic horizon,and they are merely subdivided into one suborder and two soil groups.Ferrisols are the soils that have LAC-ferric horizon but do not have ferralic horizon.and they are subdivided into three suborders and eleven soil groups.Ferralisols may correspond to part of Latosols and Latosolic red soils.Ferrisols may either correspond to part of Red soils,Yellow soils and Dry red soils,or correspond to part of Latosols and Latosolic red soils.     

中国土壤分类法中铁铝土的分类

The development of the classification of ferrallitic soils in China is reviewed and the classification of Ferralisols and Ferrisols in Chinese Soil Taxonomy is introduced in order to discuss the correlation between the ferrallitic soil classification in the Chinese Soil Taxonomy and those of the other soil classification systems. In the former soil classification systems of China, the ferrallitic soils were classified into the soil groups of Latosols, Latosolic red soils, Red soils, Yellow soils and Dry red soils, according to the combination of soil-forming conditions, soil-forming processes, soil features and soil properties. In the Chinese Soil Taxonomy, most of ferrallitic soils are classified into the soil orders of Ferralisols and Ferrisols based on the diagnostic horizons and/or diagnostic characteristics with quantitatively defined properties. Ferralisols are the soils that have ferralic horizon, and they are merely subdivided into one suborder and two soil groups. Ferrisols are the soils that have LAC-ferric horizon but do not have ferralic horizon, and they are subdivided into three suborders and eleven soil groups. Ferralisols may correspond to part of Latosols and Latosolic red soils. Ferrisols may either correspond to part of Red soils, Yellow soils and Dry red soils, or correspond to part of Latosols and Latosolic red soils.     

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.     

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.     

Characteristics and classification of anthropogenic soils in the Osnabrück area,Germany

Soils in the area around Osnabrück/Northwest Germany have been strongly influenced by man. The classification of these soils based on the German and international classification systems is problematical. Eight representative soils, two Anthrosols (plaggic and hortic), four soils affected by the coal and steel industry and consisting of distinct monosubstrata (coal and ore mining heaps, slag heap, sludge area) as well as two deposits of heterogeneous waste components (reclaimed wet land, filled quarry) were investigated. The sites are assessed in relation to their contamination by heavy metals and PAH as well as suitability for plant growth. An attempt was made to classify the soils using the current classification of World Reference Base for Soil Resources (WRB), German Soil Science Society Classification, FAO and the USA. These systems enables a satisfactory classification of two Anthrosols compared with the other soils. In the US taxonomy, the pedogenesis of technological substrata was not considered. In the FAO taxonomy, it is not acceptable to term all soils as Urbic Anthrosols without any further differentiation. This differentiation was enabled in both the WRB and the German taxonomy. In the WRB taxonomy, however, only anthropic subunits of the Regosols are included. An improvement could be achieved by the introduction of comparable subunits of the Arenosols, Durisols, Gleysols, and Leptosols. In the German taxonomy (normally soil and substrata are classified separately), the induction of toxic subunits in the presence of high soil contamination influencing the edaphon would be helpful. Furthermore, soils hardened by silica should be classified as respective varieties.     

Technosols in the World Reference Base for Soil Resources – history and definitions

ABSTRACT

The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the update 2015 of its third edition. WRB has two levels: first and second. The first level comprises 32 Reference Soil Groups (RSGs), identified using a Key. At the second level, the soil names are constructed by adding a set of qualifiers to the name of the RSG. In the WRB, diagnostic horizons, properties and materials are defined. Diagnostic materials are materials that significantly influence soil-forming processes. Diagnostic properties and horizons have a combination of attributes that mostly reflect results of soil-forming processes.

The RSG Technosols was introduced in the second edition of the WRB in 2006. In the current version of the WRB, two diagnostic materials are defined for Technosols: artefacts and technic hard material. Artefacts are substances that are created or substantially modified by humans or brought to the surface from a depth, where they were not influenced by surface processes. The technic hard material is a (relatively) continuous consolidated material resulting from an industrial process. The Technosols are at the third place in the Key after Histosols and Anthrosols. A soil is a Technosol if it has technic hard material within 5 cm or a geomembrane or a significant amount of artefacts within 100 cm. If a soil has no technic hard material and no geomembrane but a layer with artefacts that has undergone enough soil formation to develop a diagnostic horizon typical for advanced pedogenesis, the soil is excluded from the Technosols. There are specific qualifiers to further characterise the Technosols. They are also important to characterise soils other than Technosols that have artefacts or technic hard material. Human-transported natural soil material does not qualify as Technosol.     

Evaluation of World Reference Base for Soil Resources and FAO Soil Map of the World using nationwide grid soil data from Denmark

Abstract. Soil classification is a tool for stratifying and generalizing information on soil resources but most systems are tailored to handle only slightly disturbed soil. We tested the applicability of the legend of the FAO-Unesco Soil Map of the World and the new World Reference Base for Soil Resources by classifying at the highest order 831 profiles from a nationwide 7 km grid survey in Denmark, where soils are developed in Quaternary glacial and marine sediments and intensively farmed. Comparison of the variability of pH and % clay +% silt of the master horizons (A, E, B, and C) within and between the major well-drained soil groupings shows that liming, fertilizing and ploughing have produced significantly deeper A-horizons with higher pH, lower % humus and C:N ratios on the two-thirds of the country that is cultivated. ‘Anthropogenic’ mollic and umbric horizons are a common result but the liming causes a random final classification of these surface horizons and, hence, random allocation of the soils in both systems. It separates cultivated soils and their undisturbed equivalents, and results in considerable within-group variation in soil texture. Grouping of cultivated and undisturbed soils, on the other hand, results in wide within-horizon pH ranges for most groups, again compromising the advantage of making useful general statements on the basis of classification. We propose that anthropogenic mollic and umbric horizons should be allowed in any soil group and that ‘anthric properties’ should be used to distinguish between profoundly changed cultivated soils and largely undisturbed soils, hereby constructing a two-tier system within each highest-order soil group. We classified the soils according to this proposal. The results show generally narrower ranges for both pH and % clay +% silt. We evaluated the within-group homogeneity by multivariate analysis of variance of pH, % clay +% silt, % clay, % humus, C:N ratio, exchangeable cations, and CEC. The results (Wilks's Lamda) show a higher degree of group compactness compared to the original FAO and World Reference Base systems.     

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...     

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.     

中国古代土壤分类简介

我国是世界科学文化发达最早的国家之一,农业生产起源很早,有着悠久的历史。历代发展经济的方针,是以农业为基础。作为农业基本生产资料的土壤,早就为人们所重视。《管子》指出:“地者,政之本也,辨于土而民可富”;“五谷不宜其地,国之贫也”。远古以来,我国的农业科学技术,是以土壤科学为中心。数千年来,我国劳动人民在辽阔的土地上耕种生息,创造和积累了极其丰富的经验。建立在劳动人民丰富的实践经验基础上的我国古代土壤科学,造诣很深,是一丰硕的土壤科学宝库。     

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.