Physicochemical Properties of Gray Forest Soils on the Eastern Outskirts of the Trans-Ural Plateau

• Published in: Žurnal Sibirskogo federalʹnogo universiteta. Seriâ Biologiâ (Online) 2022-10, Vol.15 (4), p.471-490
• Main Authors: Kayugina, Svetlana M, Eremin, Dmitry I
• Format: Article
• Language: Russian
• Subjects: Acidic soils; Acidity; Agricultural production; Arable land; Cation exchange; Cation exchanging; Cations; Chemical properties; Chemicophysical properties; Coefficient of variation; Decomposing organic matter; Exchange capacity; Farming systems; Fertility; Forest soils; Forests; Genetic analysis; Horizon; Human impact; Human influences; Humus; Light; Physicochemical processes; Physicochemical properties; Restoration; Saturation; Soil; Soil fertility; Soil properties; Variability
• ISSN: 1997-1389; 2313-5530
• DOI: 10.17516/1997-1389-0399

Gray forest soils are the most promising for expanding the arable area in Northern Trans-Urals. The diversity of landscape and soil-forming rocks and human impact resulted in a wide range of their properties. The aim of the research is to examine the physicochemical properties of gray forest soils and determine the nature of their variability. The object of research is virgin gray forest soils (Luvic Retic Greyzemic Phaeozems). Three hundred and thirty full-profile sections were laid, their morphological description was provided, soil samples for laboratory analysis were selected according to genetic horizons. The results of the research show that gray forest soils on the eastern outskirts of the Trans-Ural Plateau have physical and chemical properties relatively favorable from an agronomic perspective. As the intensity of podzolization decreases, the total amount of exchangeable bases in humus horizons increases from 17.2 to 25.3 mmol (eq)/100 g in light gray and dark gray soils, respectively. A high degree of variation in the values of hydrolytic acidity of dark gray forest soils in Northern Trans-Urals, from 1.1 to 13.0 mmol (eq)/100 g of soil, was revealed (the variation coefficient in the humus horizon is 43 %). In light gray and gray forest soils, hydrolytic acidity is characterized by lower values: 4.6 and 5.2 mmol (eq)/100 g of soil, respectively. The absorption capacity of all gray forest soils is relatively high, even in the light gray subtype, where it varies in a wide range - from 12.2 to 31.0 mmol (eq)/100 g of soil. In dark gray soils of Northern Trans-Urals, the average cation exchange capacity is 32.1 mmol (eq)/100 g of soil, decreasing with depth. The degree of humus horizon saturation with bases in dark gray forest soils reaches 79 % of the cation exchange capacity varying from 67 to 95 %. Similar physical and chemical properties of light gray and gray forest soils make it possible to place them into one agricultural production group to develop a unified farming system that provides enhanced restoration of soil fertility. In the agricultural use of dark gray forest soils, it is necessary to take into account immensely high variability of their physicochemical properties.