The geography of Vertisols and Vertic soils in the Kuban-Azov Lowland

Abstract

The soils shown on Russian soil maps of the Kuban-Azov Lowland under the names of slitic (ver tic) and compacted soils contain diagnostic features characteristic of the type of dark slitozems and subtypes of slitic soils in the new Russian soil classification system, or Vertisols and Vertic soils in the WRB system. These are slickensides, wedge shaped structure, clayey texture through the entire soil profile, and shrinkage cracks formed during soil drying. It was found that dark quasi gley slitozems (Vertisols) occur in the central parts of the bottoms of large (> 1.5 km along the longest axis) closed depressions. Humus quasi gley slitozems (Vertic Stagnic Phaeozems (Clayic, Pachic)) are confined to the peripheral parts of the bottoms of these depressions and to the bottoms of smaller (0.8-1.5 km) closed depressions. Deeply slitic humus-quasi gley soils and deeply slitic clay illuvial chernozems (Bathyvertic Stagnic Phaeozems (Clayic, Pachic)), in which the upper boundary of slickensides is found at the depths from 100 to 200 cm, usually occur in the bottoms of closed depressions with the longest axis of less than 0.6-0.8 km and in the bottoms and on slopes of shallow flat bot tomed ravines. With respect to the distribution of Vertisols and Vertic soils, the Kuban-Azov Lowland can be subdivided into eight soil districts. In five of them, these soils occupy from 0.1% to 12.1% of the territory.

Anthropogenic impact on grain-size distribution and agrophysical properties of soils of cultivated rice lands of Kuban

“…With the same genesis of the parent rock materials, depending on the soil-forming and other natural processes (subsidence, compactness, salinization, gleyzation, etc. ), the agrophysical properties can be considerably different while having the same grain size distribution [11,12]. The comparison of agrophysical properties of soils of different genesis is given (table 1).…”

Modern characteristics of the properties of meadow-boggy soils of rice agrocenosis in the republic of Adygeya

“…At the same time, the entire profile of alluvial meadow-boggy soils is characterized by the presence of hydromorphic features in the form of rusty-ocher spots and patches of iron oxide. Ferrous forms of iron (signs of gleying) in the form of bluish-gray spots and streaks are found in the middle part of the profile, horizon "B", and the parent rocks, as a rule, are significantly gleyed [10,12].…”

Modeling of the components of the natural environment

“…These techniques help to preserve the harvest and reduce the production cost. We should note, however, that a constant increase in the yield of agricultural crops over a period of 40-50 years in the black earth soils of the south of the Russian Federation has led to a decrease in humus content from 8 to 4-6% (Zachary, 2020;Khitrov et al, 2015;Val'kov et al, 1995), while the yield of the same winter wheat increased from 3-5 to 6-7 t/ha and, similarly, the yield of other agricultural crops also increases. A paradox!…”