EUROPEAN SOIL BUREAU RESEARCH REPORT NO. 7 Present-day status of Soil Classification in Romania MUNTEANU Ioan and FLOREA Nicolae Research Institute for Soil Science and Agrochemistry, Bul. Marasti Nr. 61. Sector 1 Bucharest, Romania Email: [email protected] Abstract As everywhere the soil classification in Romania is still evolving. At the end of XXth century an updated version of the "Romanian Soil Classification System " (RSCS-1980)-(Conea et al, 1980) was issued under the name "Romanian System of Soil Taxonomy" (RSST-2000) (Florea and Munteanu, 2000). This new system incorporates the progress made in soil classification in Romania in the last 20 years as well as the progress in soil classification worldwide, mainly that evidenced by the World Reference Base for Soil Resources (FAO et al, 1998). The RSST-2000 is a hierarchical, multicategorical system including three higher level categories (class, genetical soil type and genetical soil subtype) and four lower level categories (soil variety, soil species, soil family and soil variant). Continuing the Romanian tradition the basic taxonomic unit is the genetical soil type. As diagnostic criteria at higher levels the RSST-2000 uses 29 diagnostic horizons, 23 diagnostic properties and 6 diagnostic parent materials. At lower levels 18 indicators are used. In contrast to RSCS-1980, the RSST-2000 brings some important conceptual, structural and linguistic (terminology) improvements: new diagnostic horizons and properties (e.g. limnic horizon, hortic horizon, eutric and dystric properties etc), new soil classes (e.g. Andisols) and new soil types (e.g. Limnosols, Alosols and Pelosols). Although the Romanian language is not very suitable for making composed words, at class and soil type level single word substantives were coined (e.g. Dystricambosols for Dystric Cambisols) or borrowed (e.g. Salsodisols for Saline and Sodic soils). Key words: soil classification, soil taxonomy, Romania. Introduction In Romania soil classification has a long lasting tradition. The first scientific classification of soils in our country is as old as the beginning of the XXth century and belongs to G. M. Murgoci the founder of Romanian soil science. Following Murgoci several attempts had been made to improve it but a successful one the "Romanian Soil Classification System" (RSCS) was issued not earlier than the end of the seventies (1980). The RSCS-1980 is officially still in use and proves to be efficient both in soil mapping and in soil interpretations. However, as new experience accumulated that system became partly obsolete, unevenly structured, and the nomenclature partly inadequate to match the requirements of present-day usage. The obsolescence of the RSCS 1980 became more striking when compared with the progress in soil classification worldwide as evidenced by the World Reference Base for Soil Resources -1998 (WRBSR.1998), the second edition of the USDA Soil Taxonomy, 1999 and by the Référentiel Pédologique Français. As a consequence in the last ten years a revised system of soil classification, named "Romanian System of Soil Taxonomy (RSST-2000)"1 has been worked out and published in 2000. 1 Authors: N.Florea, I.Munteanu Present-day status of Soil Classification in Romania. Munteanu & Florea 55 EUROPEAN SOIL BUREAU RESEARCH REPORT NO. 7 Differences between RSST - 2000 and RSCS - 1980 The changes introduced by RSST-2000 compared with RSCS-1980 are the followings: • Introduction of: - new diagnostic horizons: limnic A horizon, hortic A horizon, pelic, petrocalcic, cryptospodic, skeletic, anthropedogenetic, and folic horizons; - new diagnostic properties: eutric, dystric, alic and cryostagnic; - new diagnostic parent materials: fluvic, anthropogenetic, calcareous, marly, etc. - new soil classes, namely: Andisols, Protisols and Anthrisols. The last two by splitting of the former very heterogeneous class of "Undeveloped soils". - several new soil types: Limnosols (soils developed under shallow water bodies), Alosols (deep acid soils with Bt horizon), Pelosols (very clayey soils that do not meet the requirements for Vertisols). - new soil subtypes (e.g. psamic, pelic, skeletic, calcaric, eutric, distric, aluvic, cryostagnic, prespodic etc.). Uniformisation of nomenclature, by coining a single word, for naming soils at class and genetical soil type level. • Deleting the Mollisol class that was a source of confusion because the concept used in Romania was different from the original one used in the USDA Soil Taxonomy. • Regrouping of some soil types e.g. Chenozems and Cambic Chernozems (as Chernozems); Clay- illuvial Chernozems, Chernozemlike soils, Grey soils and Pseudorendzinas (as Phaeozems); Reddish Brown soil and Clay Illuvial Brown soil (as Preluvosols); Luvic Brown soil and Albic Luvisols (as Luvisols). In all these cases, the former genetical soil types are now found as genetical subtypes. The guiding principles of the RSST-2000 The Romanian System of Soil Taxonomy -2000 (RSST-2000) represents an updated version of the former Romanian Soil Classification System-1980 (RSCS-1980) whose structure was not altered and its main entities preserved. However, RSST-2000 provides a better fit of soils into the system, a more consequent use of diagnostic criteria, an increase of the practical applicability, and uniformity of soil terminology and nomenclature. The basic characteristics of RSST-2000 can be summarised as follows: a) It preserves and continues the Romanian Soil Science School tradition concerning the concept of soil as natural body resulting from the combined action over time of the soil-forming factors and processes upon the uppermost part of the Earth’s Crust. An important part of the criteria used as differentiating parameters of the system’s categories are specific "Romanians". b) In parallel with preservation of regional and national peculiarities, RSST-2000 is aligned with international standards aiming to facilitate as much as possible the best correlation with the World Reference Base for Soil Resources-1998 as well as with other world-wide classification systems e.g. USDA Soil Taxonomy. c) RSST-2000 is a multicategorial system, with two main levels: one of higher categories and one of lower categories. The basic taxonomic unit is the genetical soil type. d) The definition of each category (taxon) is operational and has the same meaning for each kind of use. The taxa (categories) refer to real, natural soil bodies that occupy distinct portions of the landscape. e) The differentiating elements between categories are those soil properties that can be directly observable in the field or those that can be deduced from other soil properties that can be observed in the field or from data of soil science combined with data of other disciplines (e.g. mineralogy, geology etc). The system also uses laboratory-based measurements as criteria (e.g. pH, base saturation degree, and soluble salt content). f) The specific properties used as differentiate may vary independently each other, and their importance depends upon their combination with other properties. g) The differentiating elements have been chosen in such a way that the soil classification does not change following cropping or other anthropic interventions of weak intensity (plowing, loosening, surficial stripping etc). h) The informational data base that has been used for compilation of the RSST-2000, assures the introduction in the system of all soils that may occur within a given area of the national territory and, in principle, of all soils presently known in Romania. 56 Present-day status of Soil Classification in Romania. Munteanu & Florea EUROPEAN SOIL BUREAU RESEARCH REPORT NO. 7 i) The RSST-2000 is a flexible system in so far as new soils that will be identified in Romania would be introduced without disturbing its general structure. Diagnostic elements used to identify soils Within RSST-2000 there is a clear distinction between the morphologic horizons (used in soil description) and diagnostic horizons and properties used to classify soils. In this system 29 diagnostic horizons, 23 diagnostic properties and 6 diagnostic soil parent materials are used. Diagnostic horizons • Mollic A horizons (Am) • Powdered Mollic A horizon (Ame) - (A horizon showing uncoated silt and sand grains on structural ped surfaces)2 • Umbric A horizon (Au) • Ochric A horizon (Ao) • Limnic A horizon (Al) - (A horizon developed on the surface of permanently submerged deposits, under shallow waterbodies) • Hortic A horizon (Af) - (A horizon resulted by intense and long-lasting fertilisation with manure and earthy materials) • Luvic E horizon (El) - (Eluvial horizon that does not meet the requirements for an albic E horizon and overlying an argic B horizon) • Eluvial Albic E horizon (Ea) - (Albic E horizon overlying on argic B horizon) • Spodic Albic E horizon (Es) - (Albic E horizon overlying a spodic B horizon) • Cambic B horizon (Bv) • Argic B horizon (Bt) • Argic-Natric B horizon (Btna) • Spodic B horizon (Bs, Bhs) • Calcic or calxic C horizon (Cca) • Salic horizon (sa) • Hiposalic horizon (sc) • Natric horizon (na) • Hiponatric or hiposodic horizon (ac) • Sulphidic horizon (sf) • Sulphuric horizon (su) • Vertic horizon (y) • Pelic horizon (Z) • Petrocalxic horizon (pc) • Fragipan (x) • Criptospodic horizon (Bcp) • Skeletic horizon (q) • Folic horizon (O) • Peaty horizon (T) • Anthropedogenetic horizon (N). Diagnostic properties • Vermic character (Vm) • Abrupt textural change (pl) • Andic soil properties • Albeluvic tonguing (E+B) (gl) • Lithic