Diagnostic criteria for lessivage of profile-differentiated soils of the Precarpathian region (Ukraine)

Abstract

Summary Profile-differentiated soils of the Precarpathian region were formed due to the combined effect of such processes as podzolization, lessivage, gley-eluvium. For the diagnosis of these soils, researchers have used different diagnostic features. The most controversial is the diagnosis of the lessivage process. Based on our own field and analytical studies, it is suggested to use the granulometric composition compared to the contents of the horizon and the silt content in argillanes for the diagnosis of lessivage argillanes within the illuvial horizon. A reliable feature of lessivage is the equal distribution of the montmorillonite group minerals within the profile, which is diagnosed by the ratio of SiO2:Al2O3 in the silty fraction, the accumulation of Fe2O3 and R2O3 in the illuvial horizon in comparison with the rock and positive values of eluvial-accumulative coefficient of oxides in the silty fraction in the illuvial part of the soil profile.

Forms of Ferrum in Profile-Differentiated Soils of Precarpathian Ukraine and Their Role in Diagnostics of Soil-Forming Processes

“…The formation of Fe-Mn neoplasms in profile-differentiated soils of PreCarpathians occurs due to the alternation of redox conditions, sporadic-pulsation water regime with the participation of specific, nonspecific microflora and glee-eluvial, segregation processes of soil formation. In the laboratory Fe-Mn washing of specific neoplasms on sieves and determination of their content and fractional composition by thermostatic-weight method has been carried out (Pankiv, 2019). Our research found that the gross content of Fe2O3 in the studied soils and especially in Fe-Mn specific tumors is significant, which indicates the important role of iron in the diagnosis of genesis and soil-forming processes (Pankiv et al, 2020a).…”

“…The profile-differentiated soils of the PreCarpathians predominate within the hills (Drohobych, Morshyn, Stevihor-Boloziv), where they occupy the ancient terrace watersheds of the third or fifth floodplain terraces. They were formed on carbonate-free alluvial, deluvial, alluvial-deluvial loamy rocks under conditions of excess moisture, stagnantwashing type of water regime under deciduous and mixed forests on the basis of the combined action of podzolization, silting, siltation and siltation added by segregation (Kanivets et al, 1975;Nikorych et al, 2003;Pankiv et al, 2017;2019). In the process of combined action of soil formation factors and soil-forming processes, sharply differentiated eluvial-illuvial types of profiles with illuminated, silicaenriched upper eluvial part and brown, dark brown (due to accumulation of Fe compounds), heavier with granulometric structure have been formed.…”

Soil-forming processes in profile textural-differentiated forest soils of the Cis-Carpathian region, Ukraine

“…Morphological features have been studied, and soil samples have been taken from all genetic horizons, soil-forming rocks, and soil neoformations (nodules, concretions, argillans, and cutans of iron oxides) in the field conditions within Neocambic Gleyic Retisols (study plot "Hirne", Figure 2) and Stagnic Retisols (study plot "Loyeva", Figure 3). All soil samples were taken in 6-fold repetition with further statistical treatment (Pankiv et al 2019a, Pankiv et al 2019b.…”

“…The granulometric composition of soil, argillans, ortsteins, concretions, and nodules have been determined by the method proposed by Kachinskii with the preparation of soil by the pyrophosphate method according to the Dolgov and Lichmanova procedure (Kachinskii 1965). Based on the results of the gross chemical composition of silt, fine soil, and soil (Pankiv et al 2019a, Pankiv et al 2019b neoformations, molar ratios were calculated according to the method proposed by Harrassowitz (profile differentiation indices) (1926), "leaching factor" according to G. Jenny's method (1931), EA coefficients of Fe 2 O 3 , R 2 O 3 , EAt (total eluvial-accumulative coefficient for all oxides) and EAm (eluvial-accumulative coefficient of all oxides except oxide-witness) according to Rode's method (2008). To establish the genesis of nodules, concretions and argillan, the accumulation factor (Cx) has been calculated (Dawson et al 1985).…”

“…The Cis-Carpathian region, located in the transition zone between the southwestern edge of the Podillia Upland and the northeast slopes of the Ukrainian Carpathians, is characterized by differences in the topography, climatic and biological factors of soil formation, which led to the formation of different soil, genesis, morphology and spectrum of soil-forming processes (Smaga 2016, Pankiv et al 2019a. The complex genetic nature of the Cis-Carpathian soils, the diversity of interpreting morphological features, the lack of uniform diagnostic features of elementary soil-forming processes (ESP) and the complexity of the analytical determination of a number of indicators have led to the discussions between representatives of different soil-science schools at their level of taxonomic classification (Pankiv et al 2019b). Profile textural-differentiated soils (non-classification concept that combines different soils with vertical differentiation of granulometric and gross chemical composition of fine soil in the soil profile) of humid regions of the world (Luvisols, Retisols, Planosols, Acrisols, etc.)…”