Polish Soil Classification, 6th edition – principles, classification scheme and correlations

Abstract

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.

Properties and classification of heavily eroded post-chernozem soils in Proszowice Plateau (southern Poland)

“…The over-high colour value did not allow us to determine the mollic/mollik diagnostic horizon in these soils in each of referenced classification systems (Table 3). According to Polish Soil Classification, 6th edition (Kaba³a et al 2019;Systematyka gleb Polski, 2019) the thickness of humus (resulting from the ploughing depth, ~20-25 cm) also did not allow the designate of mollik diagnostic horizon. Erosional degradation of humus horizons and consequently, a strong lightening of their colour due to erosion in loess areas was also reported by Novák et al (2018) and ðíñala et al (2019).…”

“…these soils would be classified as Udorthents (Soil Survey Staff 2014) or as Regosols (IUSS Working Group WRB 2015). Partly according to this approach, such soils were classified as 'pararendzinas' (Polish: 'pararêdziny') according to Polish Soil Classification, 6th edition (Kaba³a et al 2019;Systematyka gleb Polski 2019). This is allowed according to this classification, because both in the fine earth and in nodules carbonates are found (Tables 1, 2, Figure 2F) in the depth 30-60 cm.…”

Classification of mountain soils in a subalpine zone – a case study from the Bieszczady Mountains (SE Poland)

“…However, Umbrisols were also reported in the lowlands (Kristiansen and Greve 2003;OEwitoniak et al 2014;Jenèo et al 2018). Due to more strict criteria of the umbrik horizon implemented in the SGP6 (Kaba³a et al 2019), i.e. the required thickness of ≥30 cm, only two topsoil layers (in the profiles 2 and 3) met the criteria for umbric horizon.…”

“…These criteria were criticized due to inconsistence with soil habitat values (Bro¿ek 2012). In SGP6 (Kaba³a et al 2019) all the diagnostic criteria based on BS were substituted by the values of pH measured in deionized/distilled water. The analysis of the Polish soil database consisting of more than 4500 records made by Kaba³a and £abaz (2018) showed a significant correlation between BS and pH(w).…”

Mycorrhizal inoculation as an alternative for the ecological production of tomato (Lycopersicon esculentum Mill.)

“…MF spores were provided from the collection belonging to the Department of Agricultural Microbiology, the Institute of Soil Science and Plant Cultivation -National Research Institute in Puławy, Poland. The experiment was established in a plastic tunnel with the dimension of 6×30×2.80 m. The experiment was carried out on albic luvisols (cutanic) soil (Kabała et al, 2019). In each year, organic nitrogen fertilizer (Bioilsa 12.5 -NaturalCrop Poland) was used before planting plants in a permanent place using a dose of 500 kg ha -1 .…”