Czarne ziemie, w randze osobnej j ednostki, wyodrębnione zostały przez Miklaszewskiego ze względu na ich poba-giennągenezę, podmokłość oraz specyficzny typ „kwaśnej” próchnicy. Z czasem zaczęto określać tym mianem także inne podmokłe gleby z głębokim poziomem próchnicznym o różnej genezie: (1) czarne ziemie pojeziorne (pobagienne), (2) czarne ziemie błotne (z przeobrażenia gleb torfowo- i torfiastoglej owych), (3) czarne ziemie deluwialne, (4) czarne ziemie ukształtowane w procesie werty-lizacji, (5) czarne ziemie powstałe w efekcie zwiększenia wilgotności czarnoziemów łąkowo-leśnych, (6) poligenetyczne czarne ziemie z poziomem iluwiacji iłu. Klasyfikacja gleb o tak zróżnicowanej genezie musi opierać się na wspólnych kryteriach morfologicznych, to j est zgodnie z trendem wyznaczonym przez systematyki gleb Polski z lat 1989 i 2011. Jednak przynależność do czarnych ziem nie zawsze jest jednoznaczna, ze względu na nieprecyzyjne rozgraniczenie w punktach stycznych z pokrewnymi glebami, w tym z czarnoziemami (intensywność oglejenia), madami i glebami deluwialnymi (stratyfikacja materiału macierzystego i/lub poziomu mollic), vertisolami (obecność poziomów mollic i vertic) oraz glebami murszastymi (brak różnic w kryteriach diagnostycznych). Ponadto, uzupełnienia wymagają charakterystyki czarnych ziem pod kątem rodzaju oglejenia (gruntowego oraz opadowego), rodzaju węglanów (wtórnych i pierwotnych) oraz obecności poziomu diagnostycznego anthric.
The article discusses organic and organic-mineral soil transformations induced by fire. The research covered 24 soil profiles. It was primarily focused on water properties of post-fire soils, such as the hydrophobic degree, analysed by means of percent alcohol (MED) and WDPT test, and soil water capacity indicator (W1). The above indicators determine the degree of intensification of the moorsh process in post-fire organic soil horizons. Total carbon content was also determined by means of a gas method analyzer by CS . MAT 5500, as well as the level of organic material decomposition by means of the half syringe method. The achieved result suggests that the moorsh process and low temperature fires led to an increase in the hydrophobic property of soil organic matter, whereas in high fire temperature, the soil included more ash, and the hydrophilic properties were higher. The significant degree of transformation was also confirmed by the water capacity indicator (W1). It primarily concerned the upper horizons of the investigated soil profiles. The majority of the 76 analysed soil samples showed signs of secondary transformation.
Large-scale river regulation, drainage and intense farming in the Barycz valley initiated in 17th century activated a transformation of the initial alluvial and swamp-alluvial soils. Soils on the Holocene flooded terraces have deep, acid humus horizons (umbric) and gleyic properties at shallow depth, but have no stratification of parent material to a depth of 100 cm. Despite the location in the floodplain, soils cannot be classified as black-earth alluvial soils (mady czarnoziemne) using the criteria of Polish soil classification (2011). The soils on the Pleistocene non-flooded terraces have a deep, base-saturated humus horizon (mollic) and gleyic properties in the lower part of soil profile, which allows to classify them as the black earths (czarne ziemie). Prominent stratification of the parent material well preserved in these soils has no influence on their classification (due to the age sediments). Almost all humus horizons of these soils meet the definition of anthric characteristics, and more than half of the studied soils can be classified as culturozemic soils - rigosols - which emphasises the important role of man in the transformation and gaining of morphological features of these soils. The lack of precise criteria for identifying soil types in the chernozemic order of the Polish soil classification (2011) causes difficulties in the classification of soils on the river terraces, in particular, in distinguishing between black-earth alluvial soils and black earths.
Diverse chernozemic soils featured by thick mollic horizon, rich in humus, dark-coloured, structural, and saturated with base cations are relatively common in the loess-belt of SW Poland. It is postulated, that most of these soils may have similar initial (chernozemic) history of thick humus horizon, related to climate conditions and vegetation in the Late Pleistocene and the Neolithic periods. However, these soils exist on various bedrocks and under different moisture conditions that led to the development accompanying features and variable classification of soils, both in Polish and international soil classifications. The aim of the paper is to presents the most important variants of loess-derived chernozemic soils of SW Poland, in relation to local conditions, which influenced soil transformation and present spatial diversification. ‘Typical’ chernozems (WRB: Calcic Chernozems), which have a mollic horizon and secondary carbonates, but are free of strong redoximorphic features, are rather uncommon in the region. Whereas, the black earths (WRB: Gleyic/Stagnic Chernozems/Phaeozems), featured by the presence of mollic horizon and strong gleyic or stagnic properties in the middle and bottom parts of the profiles, are predominant loess-derived chernozemic soils in SW Poland. Their most specific forms, developed on the clayey bedrock, are black earths with a vertic horizon (WRB: Vertic Stagnic Phaeozems). The strongly leached chernozemic soils developed over permeable subsoils, lacking carbonates and free of (strongly developed) stagnic/gleyic properties are called grey soils, often featured by the presence of subsurface diagnostic horizons cambic or luvic (WRB: Cambic/Luvic Phaeozems).
Taking into account the fact that (a) measurement of the cation exchange capacity and base saturation is practically unavailable in the field, that formally makes impossible the reliable field classification of many soils, (b) base saturation is measured or calculated by various methods those results significantly differ, (c) base saturation and soil pH are highly positively correlated, it is suggested to replace the base saturation with pHw (measured in distilled/deionized water suspension) in the classification criteria for diagnostic horizons and soil units/subunits, both in the Polish Soil Classification and FAO-WRB. Based on statistical analysis of 4500 soil samples, the following pHw values are recommended instead of 50% base saturation: pHw <5.5 for umbric and pHw ≥5.5 for the mollic horizon, and for Chernozems, Kastanozems, Phaeozems (directly) and Umbrisols (indirectly). Furthermore, the pHw <4.7 may feature the Dystric qualifier in mineral soils and respective Reference Soil Groups of WRB; while the pHw ≥4.7 may feature the Eutric qualifier. The distinction between subtypes of the brown soils in the Polish Soil Classification may base on the pHw 4.7 or 5.0, but using different requirements of pH distribution in the depth control section. The replacement of the base saturation with pH refers to the formal soil classification only, and does not exclude the use of base saturation for professional soil characteristics.
Vertisols are characterized by high content of clay fraction that affects their specific morphological and physical features. The shrink-swell phenomena of clayey materials under specific moisture regime cause formation of cracks, wedge-shaped structural aggregates and slickensides on aggregate surfaces. It was formerly believed that these soils can be found only in tropical/subtropical zones, thus Vertisols have not been expected to form under temperate climate of Central Europe. As a result, Vertisols are insufficiently recognized and documented on soil maps in Poland, including the Lower Silesia region. The aim of this study was to examine soils developed on clayey parent materials near Strzelin, focusing on their morphology, properties and classification issues. There was confirmed that soils developed from Neogene clays have vertic and mollic horizon, accompanied by stagnic or gleyic properties. However, not all soils fulfil the criteria for Vertisols due to the presence of surface or subsurface coarser-textured (sandyor silty-textured) layers. Native differentiation of parent material and geomorphological processes were found the main factors, which control the spatial mosaic of Vertisols and black earths (Chernozems or Phaeozems).
The sixth edition of the Polish Soil Classification (SGP6) aims to maintain soil classification in Poland as a modern scientific system that reflects current scientific knowledge, understanding of soil functions and the practical requirements of society. SGP6 continues the tradition of previous editions elaborated upon by the Soil Science Society of Poland in consistent application of quantitatively characterized diagnostic horizons, properties and materials; however, clearly referring to soil genesis. The present need to involve and name the soils created or naturally developed under increasing human impact has led to modernization of the soil definition. Thus, in SGP6, soil is defined as the surface part of the lithosphere or the accumulation of mineral and organic materials permanently connected to the lithosphere (through buildings or permanent constructions), coming from weathering or accumulation processes, originated naturally or anthropogenically, subject to transformation under the influence of soil-forming factors, and able to supply living organisms with water and nutrients. SGP6 distinguishes three hierarchical categories: soil order (nine in total), soil type (basic classification unit; 30 in total) and soil subtype (183 units derived from 62 unique definitions; listed hierarchically, separately in each soil type), supplemented by three non-hierarchical categories: soil variety (additional pedogenic or lithogenic features), soil genus (lithology/parent material) and soil species (soil texture). Non-hierarchical units have universal definitions that allow their application in various orders/types, if all defined requirements are met. The paper explains the principles, classification scheme and rules of SGP6, including the key to soil orders and types, explaining the relationships between diagnostic horizons, materials and properties distinguished in SGP6 and in the recent edition of WRB system as well as discussing the correlation of classification units between SGP6, WRB and Soil Taxonomy.