Агрогенная трансформация почвенного покрова Присалаирской дренированной равнины (Западная Сибирь)

Abstract

Plowing up is a widespread type of anthropogenic transformation of soils and soil cover (SC) in the forest-steppe zone of Western Siberia. As a result of plowing up agrogenic transformation (agrotransformation) of soils causes their form and properties change, as well as the spatial characteristics of the SC. In the example of a model territory the features of changes in the component composition and structure of the SC of the Pre-Salair drained plain under the influence of arable press are studied. Automorphic soil formation prevails in the studied area, and zonal natural soils here are chernozems (clay-illuvial and migrate-micellar) and dark grays. These soils have an upper dark humus horizon, which in arable soils becomes an agro-dark humus horizon. In the studied area, an increase in number of the SC components was found due to the soils of the agrozems section and different types of agricultural soils, which leads to a diversification of the component composition. It was found that the component composition of SC shows high degree of its agrotransformation: area of arable soils is 55.6% of total area of SC. We also showed the sequence of agrotransformation for the chernozems of the model territory: chernozems, agrochernozems, agrozems, abraded agrozems, agroabrazems. Agrozems occupy a large area and have a classification diversity. Factors affecting the diversity of agrozems at the type and subtype classification level are identified: the degree of agrogenic transformation of clay-illuvial and migrate-micellar chernozems are distinguished. The low thickness of the humus horizon of soils in the pre-agrarian period during plowing leads to various degrees of their agrotransformation and classification divergence of soils. The SC structure is characterized by geometric parameters in accordance with the concept of V.M. Friedland. These are areas and dissection coefficients (minimum, maximum, average and median) of elementary soil areal (ESA) and soil combinations areal (SCA). Geometries of ESA and SCA are caused by the combined influence of terrain features and anthropogenic impact. ESA of agrotransformed soils (agrograys, agrochernozems, agrozems) have largest sizes, besides undisturbed automorphic soils; ESA of strongly transformed soils developed in temporary flow hollows have smallest sizes. The overall result of the agrogenic transformation of the SC on the studied area is a new spatial agrogenic structure. In the component composition of SC specific soils of different taxonomic levels appear.