Zakhar Sergeevich Ezhelev

The results of 60-year research on physical properties of soils in the MSU large lysimeters are discussed. The
questions under study were the elements of soil water balance, soil evolution, soil temperature regime, and transport of various substances in soil profile. The long-term changes in soil texture, soil mineralogy, and organic carbon content were observed. It was shown that the horizon sequence in soil profile affects the intensity of drainage flux and its stabilization in the long-term aspect. It was also found that the amount of the transit transfer of substances in different soil profiles depended both on profile structure and upper boundary conditions.

A comparative analysis of the composition of lysimetric waters for 2021–2022 was carried out. for two groups
of stationary soil lysimeters in the city. Th e fi rst group of lysimeters is formed by the system: fallow — grass
phytocenosis — overgrown fallow — spruce forest — mixed and broad-leaved plantation, developing on the
same type of mantle loam. Th e second group of lysimeters represents soils with diff erent types of tillage: conventional
plowing, extra-deep planting according to Bushinsky, plowing according to Mosolov, deep plowing
according to Kachinsky.
For both groups, the same type of migration of components is shown, in which the most migrating elements are
carbon, mono- and divalent cations, and chloride ion, with minimal migration of iron, manganese, and aluminum.
In the group of lysimeters under various types of vegetation, as the tree canopy develops and, accordingly, the
intensity of the biological cycle increases in migrating waters, the concentration of such important biophilic elements
as magnesium, calcium, potassium, and carbon increases signifi cantly, and among anions, chloride and sulfate ions.
Th is determines, within the framework of the cluster analysis, two diff erent subgroups in terms of the composition of
natural waters: the fi rst one is formed by the fallow-grass phytocenosis — overgrown fallow system, and the second
one combines tree plantations.
In the group of lysimeters with diff erent tillage, a cluster characterizes the composition of water in lysimeters with
reclamation plowing according to Mosolov and deep plowing according to Kachinsky. At the same time, individual
aggregates form lysimeters with conventional plowing and ultra-deep planting according to Bushinsky. This is explained
by the fact that in this group of lysimeters, the initially created soil profi le design is transformed, which is
characterized by the placement of eluvial and illuvial soil horizons in various combinations and at diff erent depths
depending on the type of plowing.

The mechanical characteristics of soils of the same genesis and diff erent land use of Syktyvkar are studied: agrodernovo-
podzolic urban-stratifi ed soil within the city, post-frost park soil, podzolic soil of suburban territory. The analysis of their relationship with the content of organic matter and granulometric composition is carried out. In
agrodern-podzolic urban-stratifi ed soil, the strength properties are largely due to the content of large granulometric
fractions (> 0.25 mm), and in podzolic soil — the content of organic matter. Rows of soils were built according
to the values of rheological parameters. The strength of structural bonds, estimated by the parameter of the initial
modulus of elasticity, is greatest in podzolic soil, a wide range of linear viscoelastic state distinguishes the horizons
of agroderno-podzolic urban-stratified soil. Both post-frost and podzolic soil have the same average values of the
starting point of the viscous flow region.