Chernozem natural zone: soil formation conditions and geographical location

Of all the variety of soils, chernozem is considered the most fertile. It contains a large amount of humus, which is required for the normal development of cultivated plants. There are different natural zones with black soil, which are actively used for agricultural purposes. All of them differ in certain features.

What is black soil

Under ordinary chernozem is a dark-colored type of soil that contains a lot of humus. It is formed on loess-like loams or clays. This occurs in the subboreal and temperate continental climate against the background of a periodically leaching or non-leaching water regime.Such soil is formed under perennial grasses.

This soil is ideal for growing different types of crops. The benefits of chernozem are explained by the high content of useful elements in it, granulometric properties and reaction, the optimal ratio of heat and moisture.

Chernozem is characterized by the following features:

1. This is a neutral soil that can be used for many crops.
2. There is a lot of humus in the composition of the soil - up to 15%. This is due to the decomposition of herbaceous and meadow-steppe plants. Humic compounds regulate the growth and development of crops.
3. The soil has a granular or lumpy structure. It contains a lot of humus. The mass does not cake under the influence of moisture and sunlight. Thanks to this, it is possible to achieve excellent gas exchange and create good conditions for the formation of plant roots.
4. The soil contains a lot of calcium - 70-90%.

Classification

Depending on the volume of humus, the following varieties of chernozems are distinguished:

• fat black soils - include approximately 9% of this component;
• medium humus - the content of the useful substance is 6-9%;
• low humus with dark gray color - include 4-6% humus;
• low humus - nutrient content does not exceed 4%;
• low humus with a light gray color - the volume of humus does not exceed 2%.

Also, chernozems differ in the thickness of the layer. According to this criterion, the following types of chernozems are distinguished:

• heavy duty - have a power of 120 centimeters;
• powerful - characterized by parameters of 80-120 centimeters;
• medium power - have an indicator of 40-80 centimeters;
• low power - parameters do not exceed 40 centimeters.

The following types of soils are distinguished by the degree of salinity:

• regular - are carbonate;
• saline - considered solonetzic-saline.

Besides this, there is the following classification of chernozems:

• podzolized - often found in deciduous forests;
• leached - observed in the forest-steppe;
• typical - formed on podzolic loams, in the forest-steppe with forbs and cereals;
• ordinary - prevail in the north of the steppes and are formed by forb-grass plants;
• southern - are found in the south of the steppes and are formed due to the decomposition of fescue-feather grass plants.

Chernozems are distinguished by excellent water-air characteristics and contain many nutrients. Their composition cannot be reproduced by adding organic and mineral supplements to the soil.

Soil formation conditions

Such soils are formed in the temperate climate zone, which is characterized by alternating drying and moistening, as well as the predominance of positive temperatures. The average annual values are +1-9 degrees. At the same time, the total amount of precipitation reaches 250-1000 millimeters per year.

These regions are characterized by a wavy-flat relief, on which ravines, gullies, river terraces are periodically found. This area is dominated by perennial herbaceous vegetation, after which many valuable substances remain in the soil.

Under certain hydrothermal conditions, plant residues decompose, and this process is accompanied by the formation of humus compounds. They accumulate in the upper layers of the soil. Together with humus, important nutrients are fixed in the soil. These include phosphorus, nitrogen, iron, sulfur and other substances.

Geographical position of chernozem soils

Chernozem is located on an area of more than 240 million hectares. On the map of Eurasia, it occupies not only the southern regions of Russia and Ukraine. Chernozems also dominate in the center of Europe. They are on the territory of Moldova and Austria. This soil is also found in Bulgaria, Hungary and Romania.

In foreign Asia, this nutrient soil is found in Mongolia and China. It also exists in America. Chernozems are found in the western United States, in the southern regions of Canada. They are also available in southern Argentina and Chile.

Where are they common in Russia?

Chernozem soils are common in different regions of Russia. In total, they occupy about 10% of the country's territory. At the same time, the most fertile domestic soils do not prevail in pure steppes. They are characterized by the location in the south of the forest-steppe zones. It is in these areas that there are good conditions for the free accumulation and decomposition of organic matter. At the same time, it is not affected by the washing regime.

The border of black soil distribution in Russia is located near Ukraine and Belarus. On the north side, this zone is limited by the following nodal points;

• Novosibirsk;
• Eagle;
• lower reaches of the Kama.

In the southern regions, chernozems extend to the following borders:

• Don;
• Kuban;
• the upper reaches of the Terek.

Also, there are black earth areas in the foothill regions of Altai. It is important to consider that the geographical location directly affects their quality characteristics. The most valuable are the lands around Tambov, Kursk and Voronezh.

It should be taken into account that uncontrolled intensive agriculture, violation of agrotechnical rules, excessive use of fertilizers negatively affects the quality of black soil.

Most of the nutrient soils are located in Western Siberia. However, in this zone, chernozems freeze to a great depth. Below, loess and loess-like rocks are predominantly located. Siberian chernozems are mainly localized in the steppes and forest-steppe zones.

Main problem

Steppe soil cannot always remain fertile. Its main enemies include strong winds and water erosion. Under the influence of these processes, hundreds of thousands of hectares of valuable land become unsuitable for growing cultivated plants.

This is why it is so important to provide reliable protection for black earth soils. For this purpose, it is necessary to plant strips of trees around the perimeter of the fields. Such forest plantations help protect nutrient soils from the negative effects of water and wind.

Chernozems are considered valuable soils that are perfect for agriculture. Such soils contain many nutrients and ensure the full development of cultivated plants. At the same time, it is important to provide nutrient soils with reliable protection from the influence of negative factors.

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