The agricultural value of rendzina soils depends on many factors, including type of parent rock, texture of arable layer, admixture of post-glacial materials and occurrence of coarse fragments. Over 97% of rendzinas in Poland are arable soils, and less than 3% are under permanent meadows and permanent pastures. Rendzinas are soil of high production potential for agriculture. Almost 75% of them were included in the wheat complexes (from 1 to 3) while about 10% are weak and very weak rye soils (complex 6 and 7) in Polish land suitability system. Groups of rendzinas identified for agricultural purposes and the principles of their identification were established on 1950s and 1960s when bonitation maps and soil-agricultural maps were prepared. These principles have not changed so far, therefore the purpose of the work was to describe the divisions of these soils and the characteristics of their properties on the example of arable soils based on the available data.
The aim of the paper was to present the correlation between soil types specified in the sixth edition of the Polish Soil Classification (SGP6 2019) and Polish bonitation classification. The comparisons included two categories of agricultural land: arable soils and soils of permanent grasslands. In Poland bonitation maps are one of the oldest documentations regarding soil cover. They were elaborated in an uniform manner and based on the field examination of soil profiles. Soil information reflected specific rules adopted in the soil quality classification, including identification of soil types based on genetic criteria and recognition of appropriate sequence of specific horizons in the soil profile. Publication of the sixth edition of the Polish Soil Classification enabled the attempt to adjust soil units (soil types) specified in both systems. Despite the distinction of new soil units in the Soil Classification of Poland (SGP6 2019), the usage of bonitation maps and classification protocols should not pose major difficulties in reinterpretation of soil types. This indicates on the possibility to introduce, similarly to year 2012, the terminology adapted to the requirements of modern soil science knowledge without causing significant changes in the soil-valuation table.
The purpose of the paper was the description of classification of chernozems applied in agriculture, the agricultural suitability of these soils, as well as processes contributing to their degradation. The study showed that the principles of chernozems classification into subtypes and varieties have not changed significantly since the introduction of the bonitation classification and legend of the soil-agricultural map. Lower-order units in chernozems type include typical and degraded chernozems considering deluvial varieties for both units. Chernozems are one of the most fertile soils in Poland, mostly classified from I to III bonitation classes and 1, 2 and 8 of the soil suitability complex. They constitute only 0.8% of the total area of the country, and their largest areas are located in : Opolskie, Świętokrzyskie and Lubelskie Voivodeships. Intensive agricultural use causes that chernozems are subject to progressive degradation mainly due to plaugh and water erosion as well as acidification of the crop layer.
Agricultural soil maps (ASM), prepared since mid-1960s until 1980s and digitalised recently, are important source of information on the quality and spatial variability of arable soils in Poland. Basic standard information in each map contour includes the indication of a (genetic) soil type (often also the subtype or variety related to parent material or other specific properties), soil texture classes throughout the profile, and the category of soil agricultural suitability, which covers the complex information about the soil conditions, land morphology, climate and moisture regime. Unfortunately, the genetic classification on ASM is simplified compared to soil classifications in Poland and does not reflect numerous modernisations of the classification systems, including the modifications of existing units and newly introduced soil types and subtypes. Thus, the reinterpretation of ASM is necessary to simplify the further use of ASM by various users, to allow the creation of modern soil maps based on archival databases, and to correlate the soil data with other modern national and international classifications. This paper includes a proposal of equivalents for the soil units indicated in agricultural soil map (using all soil data available in a map contour), correlated with a recent, the 6th edition of Polish Soil Classification.
The aim of this research was to determine the effect of thermal conversion temperature and plant material addition to sewage sludge on the PAHs content and the activity of selected γ-radionuclides in biochars, and to conduct an ecotoxicological assessment. The pyrolysis of the mixtures of sewage sludge and plant materials at 300°C and such temperature caused an increase in the contents of 2- and 3-ring hydrocarbons. During the pyrolysis of organic materials at 600°C, the amount of the following compounds was reduced in biochars: benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene. Among γ-radioisotopes of the elements, natural radiogenic isotopes were dominant. 137Cs was the only artificial radioactive isotope. The pyrolysis of the mixtures of municipal sewage sludge and plant materials revealed that isotope 40K had the highest radioactive activity. In the case of other analysed nuclides, activities of 212Pb, 214Pb, 214Bi, and 137Cs were determined after the sample pyrolysis. The extracts from the mixtures of sewage sludge and plant materials were non-toxic to Vibrio fischeri.
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.