The Romanian soil classification system currently in use, SRTS-2012, was made correlated with the previous most recent two systems – SRCS-1980 (used in the period 1980-2002) and SRTS-2003 (used in the period 2003-2012), in order to accurately translate the previous soil descriptions into the current terminology. For that, related to the diagnostic and taxonomic elements (terms) existing in
... [Show full abstract] SRTS-2012, some new terms and some "modified terms" were defined. The terms of last category are variants of standard SRTS-2012 terms, defined to be accurate translations of the previous systems' terms having corresponding current system terms with non-negligible definition differences. The previous systems' terms may be translated into one corresponding term (standard, modified or new-defined) or into a combination of terms (given that a soil described in a previous system may be translated into a soil association). Some sets of new terms were introduced also for other needs: description of the "land conditions" (relief, hydrology and climate) and "association modes" (frequency, weighting) of soils, description of the "non-soil" areas to be represented on soil maps and other soil characterisations. A notation (specialised language) for mnemonic formalised description of soils is used to provide clear and unambiguous term translation and soil association definition. For that, mnemonic symbols (suggestive abbreviations easy to remember) are defined for each term, including compound symbols (formed by concatenating some different mnemonic sub-codes). The SRTS-2012 soil classification system supplemented with the modified terms and the new terms defined as above forms the "SRTS-2012+" soil classification system. It is presented as a Dictionary of terms, including the direct correlation of the terms of the previous systems SRCS-1980 and SRTS-2003 with their corresponding SRTS-2012+ terms (standard, modified or new-defined). The main definition specifications of terms are given, including the differences between the definitions of the modified terms related to the definitions of their corresponding standard terms. The Dictionary is structured in categories of soil diagnostic and taxonomic elements: (i) main soil attribute indicators for defining diagnostic and taxonomic terms, (ii) diagnostic elements (65 horizons, 24 properties and 11 parent materials), (iii) high taxonomic level categories (12 soil classes, one class of non-soils, 38 soil types, five non-soil types, 117 qualifiers for defining soil subtypes, 13 qualifiers for defining non-soil subtypes and 14 specifiers for soil characteristics), (iv) low taxonomic level categories (61 soil particular characteristics and 203 other low level qualifiers for defining the varieties, species, families and variants of soils and non-soils), (v) complementary low taxonomic level categories (103 complementary low level qualifiers for defining the land conditions and association modes of soils) and (vi) major soil typological units ( 854 type-subtype combinations) existent in Romania (including the translation of the major soil units defined in the previous systems) and major non-soil typological units ( 20 type-subtype combinations).
Key words: soil classification, soil taxonomy, soil classification systems, soil classification system correlation, Romania.