Spatial variability of the power of genetic horizons of gray forest soils of Northern Trans-Urals

Gray forest soils are the most promising for expanding arable fund of the Northern Trans-Urals. Unlike chernozems, they are characterized by significant variation in the main morphogenetic properties, which makes it difficult to use them efficiently. The purpose of the study was to analyze spatial variability of the power and lower limit of genetic horizons of light gray, gray and dark gray forest soils of the Northern Trans-Urals. Statistical processing of the results of the description of 330 full-profile soil sections was performed in Microsoft Excel 2010. It was found that the subtypes of gray forest soils differed significantly in genetic horizons. In light gray and gray forest soils proper, there was eluvial horizon (A1A2), differing in color and structure. The analysis of descriptive statistics made it possible to conclude that there was high variability in the thickness and lower boundary of eluvial horizon within considered subtypes of gray forest soils. In dark-gray forest soils, eluvial horizon was not found, only on certain sections there were podzolic signs, expressed as silica powder. The subtype of gray forest soils was characterized by average level of fertility and could be considered as potentially significant soil when expanding the arable fund. The soil profile of dark-gray forest soil was most closely approximated by morphogenetic features to the chernozem of the forest-steppe zone of the Trans-Urals. Considerable variability in the depth of boiling line in gray and dark gray forest soils was revealed, which was a regional feature of the soil cover of Northern Trans-Urals and could have an explanation for spatial heterogeneity of the fertility elements of this soil subtype.