Mathematical models of soil reference standards of pine-forest hollows of ancient streamflows in the Altai Region

The regional soil reference standards were developed in accordance with the natural geomorphological soil zoning of the Altai Region. There are 44 soil districts in the territory of the Altai Region. The intrazonal soil district of the pine-forest hollows of ancient streamflows (17th soil district) has an outlier pattern and consists of 4 sections - Barnaulskaya, Kasmolinskaya, Kulundinskaya and Burlinskaya hollows of ancient streamflows. The quantitative models of regional soil reference standards of the 17th soil district have shown that their association with a certain ancient streamflow hollow has a lesser effect on soil property differentiation than the genetic horizon and belonging to a taxonomic group. The differences in soil physico-chemical properties are due to the differences in the particle-size composition. Sandy loam and light-loamy types of sod-podzolic soils of the Kasmolinskaya and Kulundinskaya hollows of ancient streamflows are characterized by higher values of humus content, humus-eluvial horizon thickness, total absorbed bases and mobile phosphorus content. The quantitative characteristics of properties for sod-podzolic soils of 3 genera were determined: ordinary, poorly differentiated and pseudofiber ones. In accordance with the substantial genetic classification of soils in Russia, the studied soils correspond to the trunk of underdeveloped soils of two types - psammozems and humus psammozems. Sod-podzolic underdeveloped soils correspond to typical psammozems. Sod-podzolic ordinary soils correspond to the type of humus typical psammozems, and sod-podzolic pseudofiber soils - to humus pseudofiber psammozems. Thus, in accordance with the substantive-genetic classification, the studied soils belong to a higher level of the taxonomic system than that according to the profile-genetic classification.