Chestnut soils: characteristics and conditions of formation, fertility and where they are

Chestnut soil types are found in arid steppes and semi-deserts located in the temperate zone. They are lighter than chernozems and can be chestnut, dark chestnut, or light chestnut. The color of the earth is due to the lower content of humus. The share of this substance is 1.5-4.5%. This type of soil is formed on loess, carbonate sands, and alluvium. Areas with these soils are characterized by a sharply continental arid climate.

Features

Such soils are found in dry steppes dominated by chernozems. These are mainly large strips that run from the western part of Altai. In the eastern regions, the number of such soils is much less. They are found only in the lowlands in the form of separate patches.

These soils are common in the steppes of eastern Transbaikalia, in the south of the West Siberian Plain. They are also found in the hilly terrain of Kazakhstan, Astrakhan region, Dagestan. The south of Ukraine is also considered to be the geographic location of chestnut lands.

The granulometric composition of this type of soil is characterized by some features. They are high in s alt. This is due to the land's ability to absorb sodium.

The silty part, as a rule, is uniformly distributed along the soil profile. However, with varying degrees of salinity, it can shift from the upper layer to the lower structures.

Compared to fertile black earth, chestnut soils contain less humus. Its layer is no more than 40-55 centimeters. Therefore, the soils have a brown color.The structure of this soil has clearly defined horizons. The top contains more humus. The layer below it is considered transitional and contains much less humus.

Then there is another transitional horizon, which is distinguished by lumpy and flat fractions with a rough structure. At the bottom there is a structureless illuvial-carbonate layer of high density. At depth, it transforms into the parent rock.

Natural conditions of soil formation

The process of soil formation depends on the influence of many factors. These include climatic conditions, relief, vegetation.

Climate

Chestnut soils are formed in the zones of dry steppes. They have a continental climate. In winter, low temperatures and an insignificant layer of snow are observed in this area. Summer is considered very dry.

Of particular importance is the effect of the anticyclone on noticeable radiative cooling in winter. The zones of chestnut soil formation are characterized by uneven precipitation. The close location of groundwater contributes to the moistening of only the upper layers. At the same time, high evaporation leads to a moisture deficit in the lower structures. The moisture coefficient of this type of soil is 0.25-0.45.

Relief and soil-forming rocks

The structure of chestnut soils depends on the relief. For the most part, it is flat. However, it is almost always supplemented by estuaries, depressions and depressions. Therefore, the composition of the soil and the humus content in it may differ.

It is important to take into account the microrelief - the state of the top layer of the earth. This parameter is closely related to plant and zoological communities.

Rocks that contribute to the formation of chestnut soils are presented in the form of Tertiary and Cretaceous deposits.They mainly include clay and loess-like loams. In different regions, these lands may differ, but almost all of them are saline and include calcareous fractions and carbonates. The thickness of the humus horizon of such soils is 15-30 centimeters.

Vegetation cover

Vegetation influences soil structure. When changing from one variety to another, new conditions for soil formation are formed, as the process changes. This process is characterized by zonal features. At the same time, steppe vegetation most often replaces forest vegetation, which provokes leaching and soil degradation.

As a result, the formation of chestnut soils takes place under the complex influence of many factors. It is associated with an arid warm climate, the annual death of plants, enrichment with various substances and s alts.

Profile structure and classification

Chestnut soils are widespread. They have a characteristic profile structure, which includes the following components:

1. A - is a humus horizon, the thickness of which is 15-30 centimeters. It is characterized by a dark gray or chestnut color, as well as a lumpy texture.
2. B1 is a transitional horizon, which has a thickness of 10-25 centimeters. It is distinguished by a richer brown color and dense structure.
3. B2 - is a transitional horizon with an uneven color. On a brown background there are spots and streaks of humus. It is characterized by a lumpy-prismatic structure.
4. ВСК - illuvial-carbonate horizon, the thickness of which is 40-50 centimeters. This layer is characterized by yellow-brown or yellow color and high density.
5. SS is the parent rock with gypsum exudates. It starts at a depth of 110-200 centimeters and has a looser and wetter texture.

Clay

The main characteristic of such soil is the high content of clay. The soil is highly plastic and rolls into a bundle and a ring. Such land is not suitable for plants, as it hardly passes water and air.

Heavy loamy

Such types of soil are characterized by high cohesion and moisture capacity. They are well supplied with nutrients and contain quite a lot of humus. At the same time, it is difficult to cultivate such lands.

Medium loamy

They contain approximately 60% clay and 40% sand. They contain many minerals and useful plants. Due to this, such soils are suitable for the cultivation of many plants. Such soil is considered permeable and easily saturated with oxygen.

Easy loamy sandy loamy

Such soils are easy to work, because they are called light. They are distinguished by excellent water permeability and favorable air conditions. Also, these lands are rapidly warming up. At the same time, light soils also have disadvantages - first of all, low moisture capacity.

Sandy

These soils are light and have excellent water permeability. They are well breathable, but have a low moisture capacity. Therefore, plants that grow in such soil are deficient in moisture. Another disadvantage is susceptibility to erosive processes.

Where is it used?

Soils of chestnut type are distinguished by the presence of very sparse and stunted vegetation. In most cases, xerophytic plants are found here, which are adapted to survive in critical conditions of heat and moisture deficiency.

In nature, the vegetation of chestnut formations is considered relatively poor. Fescue, wormwood, feather grass and herbs grow well on them, which are resistant to unstable moisture.

However, with proper irrigation, the economic use of such soils can be very successful:

1. Light chestnut soils and soils with a high content of solonets are suitable for the cultivation of sweet clover, alfalfa, wheatgrass - herbaceous crops that are resistant to s alt and drought. Livestock are pastured on these lands. With proper fertilization, soil fertility can be significantly increased.
2. Dark chestnut soils are more fertile. On them you can grow any vegetable plants, horticultural and melon crops. Such lands are suitable for the cultivation of corn, sunflower, millet. You can also plant durum wheat here.

For farming on chestnut soil types to be successful, they need to be properly fertilized. With additional irrigation, it is worth using compositions with a high content of phosphorus, potassium and nitrogen. In the absence of irrigation, you can make a little phosphorus additives.

Flaws

For the successful use of chestnut soils in agriculture, it is required to add mineral and organic preparations to them. Light chestnut soils are not well suited for growing crops. They are more often used for pastures. They contain little humus and hardly pass moisture. Another disadvantage of such soils is the tendency to accumulate many harmful compounds.

Chestnut soils are considered quite fertile and can be used for agricultural purposes. However, for this they need to be properly irrigated and fed.

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