Recent erosion-accumulation processes response in a soil classification system – a review

Abstract

The redistribution of soil mass in erosion-accumulation areas leads to many changes in soil properties and to changes in the horizonation of soil profiles. Research on soils occurring in erosion-accumulation areas is not sufficiently developed in terms of their classification. Especially colluvial soils formed by accumulation in toe-slope positions are particularly problematic, in various classifications they are ordered into different taxonomic levels, i.e. in many respects inconsistent and unsystematic. The aim of the presented contribution is to characterize and classify colluvial soils for the new version of the Morphogenetic Soil Classification System of Slovakia, i.e. to find a taxonomic level within the classification system, based on the knowledge gained from soil surveys in erosion-accumulation areas of Slovakia. An overview of classification approaches used for these soils in some national and international soil classification systems (WRB 2015 and 2022) was made. The terminologically unsuitable concept of colluvial soils, which is usually linked to geomorphology or sedimentology was resolved in WRB 2022 by introducing a new classification concept distinguishing solimovic material which is a recent heterogeneous, predominantly soil material with organic matter content, resulting from the transport of eroded material down by the slope and its accumulation in lower concave positions. Typification of soil profiles and definition of diagnostic criteria is a tool for creating a taxonomic unit at the level of soil type, subtype or form. The demand to distinguish colluvial soils as a new soil type was initiated by practical land users from the perspective of evaluating production potential and soil quality.

Keywords: soil classification system, soil taxonomy, colluvial material, solimovic material, soil diagnostics