Soils of the middle belt of Russia. Characteristic. Sod-podzolic soils

Podzolic soils of Russia are considered to be one of the most widespread in the middle belt. They are considered the most infertile. These soils are structureless, characterized by high acidity, and also by the presence of a podzolic horizon. Often they are formed under the canopy of the coniferous forests.

In the central part of the country, soddy soils are also common. They are formed under the influence of grassy vegetation. Among the features of soddy soils, there is an increased content of humus, a practical or partial absence of podzol, a lumpy-granular structure. As a rule, they are characterized by high fertility.

Sod-podzolic soils are the main ones in the non-chernozem zone of the country. They include the upper sod and the lower podzolic layer. These soils are characterized by low fertility, low (from 0.5 to 2.5%) humus content and acidic reaction (pH 4-5) of the soil solution. In addition, the humus horizon has a small thickness (ten to twenty centimeters).

As a rule, sod-podzolic soils have a humus rich top layer. At the same time, on carbonate moist rocks, the processes of plant decomposition and their transformation into humus proceed much faster.

Sod-podzolic soils are characterized by an extremely low content of nitrogen and phosphorus (in the form that the plants assimilate). On soils that differ in their light composition (sandy loam and sandy), a lack of potassium is noted.

All sod-podzolic soils contain very little iodine, zinc, copper. Together with this they differ in excess of manganese. To increase the fertility of these lands, it is necessary to regulate the water-air regime, especially on excessively moistened areas. The fertile layer is increased by introducing organic fertilizers into the soil. The acidity is reduced by liming.

The sod-podzolic type of soils is prevalent mainly in the northern half of the non-chernozem zone. Their formation occurs not under the forest, but mainly in the meadows. In these territories, as a result of the death of grass, many years of grassy felts appear on the surface, and the root remains are found in the thickness. In this case, often interlacing roots with the top of plants. As a result, a single layer is formed. It is distinguished by a large amount of plant residues.

For the sod-podzolic type of soils, the presence of a whitish interlayer is characteristic. Its structure and color resembles ash from the oven. In weakly podzolic soils, the thickness of the layer is several centimeters, and the soil stratum itself is of the order of twenty to twenty-five centimeters. In connection with this, such lands do not need radical improvement.

The reverse situation with strongly podzolic soils. The use of such lands is possible only after work on their improvement. In addition to the low content of nutrient components, the absence of non-capillary porosity, and also the unfavorable water-air regime, fatty clay may lie at a shallow depth (about thirty to forty centimeters), and below it is a thin but firm and dense "flagstone" consisting mainly of Of iron oxides. In connection with this, sod-podzolic soil needs to be dug to a depth of at least forty to forty-five centimeters, or to dig very wide pits no less than fifty centimeters deep.

Due to the fact that some of the dying plants remain in the thickness of the earth, where access to air is difficult, bacterial decomposition and the subsequent penetration of organic matter into the more deeply embedded layers occurs only partially. Humus acids are formed during the decay, which turn (as a result of some chemical reactions) into humins and subsequently take part in the formation of fresh humus and the lump structure of the upper soil layer.