V.V. Dokuchaev called chernozems the “king of soils” due to their high fertility. About the origin of chernozems there are various hypotheses and theories. Some researchers were inclined towards the marine origin of chernozems, that is, they considered them as marine silt remaining after the retreat of the Caspian and Black Seas. Other scientists considered the black soil to be the product of redeposition of black Jurassic shale by glacial seas and icebergs. Then the theory of the swamp origin of chernozem was put forward, according to which the chernozem zone in the past was a heavily swampy tundra. During the drainage of the territory with the onset of a warm climate, the decomposition of swamp and tundra vegetation, swamp silt and the settlement of terrestrial vegetation occurred, as a result of which chernozems were formed.

More accurate ideas about the origin of chernozem belong to M.V. Lomonosov, who in his work “On the Layers of the Earth” (1763) wrote that chernozem is not a primitive or primordial matter, but came from the decay of animal and plant bodies over time.

The theory of the plant-terrestrial origin of chernozems was expressed by F. Ruprecht in his work “Geobotanical study of chernozems” (1866). He considered the emergence of black soils as a result of settlement herbaceous plants and the accumulation of humus during their decomposition, without attaching importance to other soil-forming factors.

P. A. Kostychev in his work “Soils of the Chernozem Region of Russia” (1886) assigned a special role to the root systems of herbaceous plants in the accumulation of humus.

V. R. Williams believed that the genesis of chernozems is the result of the development of the turf process under meadow steppes.

Origin of chernozems on scientific basis was proven by V.V. Dokuchaev in his work “Russian Chernozem” (1883). He considered the formation of chernozems to be the result of the accumulation of humus in the rock “from the rotting of grassy steppe, rather than forest, vegetation, under the influence of climate, age of the country, vegetation, terrain and parent rocks.” He associated the type of vegetation, the rate of its development, the nature and speed of the processes of decomposition of plant residues with climate.

Subsequently, the Chernozems were studied by many researchers (N. M. Sibirtsev, I. V. Tyurin, P. G. Aderikhin, E. A. Afanasyeva, E. A. Samoilova, M. M. Konokova, etc.), through whose works it was established that chernozems are soils formed under perennial herbaceous vegetation of forest-steppe and steppe under conditions of non-leaching or periodically leaching water regime. The leading process of soil formation is the intensive turf process, as a result of which a powerful humus-accumulative horizon A develops, nutrients accumulate and the soil is structured.

The herbaceous community consists predominantly of grasses and forbs with a powerful reticulated fibrous root system.

The annual litter is 20...30 t/ha, most of it (65...75%) falls on the root mass, which is rich in protein nitrogen and bases (calcium, magnesium). The litter is decomposed mainly by spore-forming bacteria and actinomycetes with sufficient oxygen access, optimal moisture, and without intensive leaching in a neutral environment. Every year, 600...1400 kg/ha of nitrogen and ash elements are supplied with litter. The ash content of the litter is 7... 8%.

In the spring, with sufficient moisture, organic matter quickly decomposes, releasing plant nutrients. In summer, the moisture supply decreases to the wilting moisture content. Under such conditions, the mineralization of organic residues is suspended, as a result of which humus is formed and accumulates. Due to the shallow filtration of atmospheric precipitation water, nutrients accumulate in the upper horizons. Calcium promotes the fixation of humus. Winter cooling and freezing of soils also contribute to the accumulation of humus, since when low temperatures Ah humus denaturation occurs. In summer during drying and in winter during freezing, humic substances become fixed and become more complex. Their composition is dominated by humic acids and calcium humates, leading to the formation of a water-resistant granular structure. This is also facilitated by carbonate soil-forming rocks, high ash content of plant residues, and the saturation of ash with bases. The most favorable conditions for chernozem formation are characteristic of the southern part of the forest-steppe. In the steppes, there is a moisture deficit, the amount of incoming litter decreases, therefore, the intensity of humus formation decreases.

The classification of chernozems was first given by V.V. Dokuchaev, who identified them as an independent type and divided them into watershed, slope and terrace. Much attention classification of chernozems was given by N.M. Sibirtsev, S.I. Korzhinsky, L.I. Prasolov, P.G. Aderikhin and others. This problem is covered in the most detail in the multi-volume publication “Chernozems of the USSR”. Currently, chernozems are united into facies: warm Southern European, temperate Eastern European, cold Western and Eastern Siberian, deeply frozen Eastern Siberian. The facies of the zone are divided into subzones-subtypes: in the forest-steppe - podzolized, leached, typical, and in the steppe - ordinary and southern chernozems. Optimal conditions for the formation of chernozems develop in the southern part of the forest-steppe (typical chernozems), where the largest amount of plant mass is concentrated and a favorable hydrothermal regime has been established.

Chernozems are divided into types according to the thickness of the humus horizon, the humus content and the degree of severity of the accompanying process. According to the thickness of the humus horizon (A + AB), chernozems are divided into super-deep (more than 120 cm), powerful (80... 120 cm), medium-deep (40...80 cm), thin (25...40 cm), very low-power (less than 25 cm). Based on the humus content, there are rich (more than 9%), medium-humus (6%...9%), low-humus (4%...6%), low-humus (less than 4%) chernozems. According to the degree of severity of the accompanying process, chernozem soils can be weakly, moderately, strongly solonetzic; weakly, moderately, highly leached, etc.

The generalized profile of chernozems has the following morphological structure: A d - steppe felt up to 5 cm thick, consists of roots and intertwined stems of grasses on virgin soil, absent in arable soils; A - humus-accumulative horizon with a thickness of 40...130 cm or more, dark gray or black, granular or granular-lumpy, with beads on the roots of plants; AB - transitional dark gray humus horizon, granular-lumpy in structure, with noticeable browning towards the bottom of the horizon or with dark brown spots; B - horizon of humus streaks 40...80 cm thick, brownish-gray, lumpy, often divided according to structure and degree of humus content into subhorizons B 1, B 2, B 3; these horizons contain calcium carbonates in the form of pseudomycelium, crane grass, and white-eye (with the exception of highly leached and podzolized chernozems); BC K - illuvial-carbonate horizon, transitional to the parent rock, brownish-fawn, cloddy-prismatic; C - fawn soil-forming rock with carbonate secretions, and in southern chernozems with gypsum. There are molehills throughout the profile; the transitions between horizons are gradual.

Podzolized chernozems (Fig., a) are developed under broad-leaved grassy forests on loess-like and cover loams and loess. The thickness of the humus horizon (A + AB) varies from 30...50 cm (cold western and central Siberian facies) to 70...100 cm (warm southern European facies). Horizon A is predominantly dark gray, granular in structure, and when plowed, lumpy. In the AB horizon, a grayish tint is observed (a whitish coating of siliceous SiO 2 powder on structural units). Horizon B has a nutty or nutty-prismatic structure; on the edges of structural units there are brown films, humus coatings, and siliceous powder; more dense, with a gradual transition into soil-forming rock C. Soils boil from a depth of 130... 150 cm. The horizon BC K contains carbonates in the form of calcareous tubes, cranes, and pustules.

Slightly podzolized chernozems have a siliceous powder in the lower part of the AB horizon and in the B horizon, and medium-podzolized ones - throughout the humus layer and in the B1, B2 horizons.

Podzolized chernozems are divided into main genera: ordinary, merged, poorly differentiated, and non-carbonate.

The reaction of the upper horizons is slightly acidic or close to neutral (pH 5.5...6.5). The absorption capacity is 30...50 mg eq/100 g of soil; the soil absorption complex is saturated with bases, and the AB horizon contains exchangeable hydrogen (up to 3%). Horizon A contains 5...12% humate humus. In horizon B, an increase in silt content is observed.

Leached chernozems (Fig., b) are formed under forb-grass vegetation. Their profile clearly shows the dark gray humus horizon A. It is loose or weakly compacted and has a lumpy-grained structure. There is no whitish siliceous powder in this horizon. Horizon AB with a thickness of 30...50 cm in the East Siberian facies to 80...150 cm in the warm facies, dark gray with a brownish tint. Beneath it lies a compacted brownish carbonate-free horizon B with a thickness of 20...50 cm, with humus streaks, coatings and films along the edges of a lumpy-nutty or lumpy-prismatic structure; the transition is gradual. Horizon BC K is illuvial-carbonate, fawn, compacted, nutty-prismatic, with efflorescences, veins, mycelium, powdery accumulations, and carbonate craters. S to - fawn carbonate soil-forming rock. Gypsum and readily soluble salts are absent.

The following types of leached chernozems are distinguished: weakly leached (the boiling line passes no more than 20 cm from the lower boundary of the AB), moderately leached (at a depth of 20...50 cm from the boundary of the humus layer), highly leached (below 50 cm from the boundary of the AB) . A feature of these soils is the absence of free carbonates in horizons A and AB.

Typical chernozems (Fig., c) are formed under forb-grass vegetation on loess, loess-like and cover loams. They are characterized by a large thickness of the humus layer - from 50...70 cm (cold facies) to 100...190 cm (warm facies), the presence of carbonates in the form of mycelium, calcareous tubes in the AB horizon. More often, carbonates are observed from a depth of 60...70 cm. Horizon A, up to 130 cm thick, is black or grayish-black, granular, and AB is dark gray with a barely noticeable brownish tint, often with darker streaks. Below AB lies a grayish-brown compacted illuvial-carbonate horizon B k with tongues and streaks of humus, a lumpy-prismatic structure, with carbonates mainly in the form of mycelium, efflorescences, and cranes. This horizon gradually turns into the BC K horizon - pale-brown, transitional to the rock, with a significant number of carbonate veins and cranes. C to - carbonate, soil-forming rock of fawn color. Gypsum and readily soluble salts are absent throughout the entire soil profile. There are many molehills in the soils.

Ordinary chernozems (Fig., d) are distributed under steppe forb-fescue-feather grass vegetation. These soils are less thick compared to typical chernozems. Their humus horizon ranges from 35...45 cm (cold East Siberian facies) to 80...140 cm (warm facies). The soils have a brownish tint against a general dark gray background and a lumpy structure of the AB horizon. The B horizon (humus streaks) often coincides with the carbonate horizon either B k or BC K. The structure of this horizon is prismatic, the color is brownish-fawn. Carbonates are represented by spots of white-eye and pseudomycelium, powdery impregnation. Sometimes, at a depth of 200...300 cm, easily soluble salts and gypsum are released. S to - fawn carbonate soil-forming rock. There are many molehills in the soil profile.

Rice. The structure of the chernozem profile: a - podzolized; b- leached; c - typical; g - ordinary; d - southern

Southern chernozems (Fig., e) were formed under fescue-feather grass steppe vegetation. They have a small humus layer (from 25...30 to 70...80 cm). Horizon A is 20...30 cm thick, dark gray with a brown tint, lumpy and granular-lumpy structure. Horizon AB (30...40 cm) is brownish-dark gray, nutty-lumpy, compacted. Below lies the carbonate horizon B k, brown with streaks of humus, compacted, nutty-prismatic, containing mycelium, efflorescence, and powdery carbonate secretions. BC K - brownish-fawn illuvial-carbonate horizon, compacted, prismatic, with a large amount of white-eye. C is a pale-colored carbonate rock, from a depth of 150...200 cm there are gypsum deposits, and from a depth of 200...300 cm - easily soluble salts. Molehills are observed in the soil profile.

Cis-Caucasian chernozems form a unique group. They have a dark gray surface color with a brownish tint and a thick humus horizon (120...150 cm or more). These soils boil already in the A horizon.

Meadow-chernozem soils develop under conditions of increased moisture on poorly drained plains, in low relief elements (depressions, hollows, estuaries) under grass and forb vegetation. Groundwater lies at a depth of 3...6m. Meadow-chernozem soils are semi-hydromorphic analogues of chernozems. They are distinguished by a darker color of the humus horizon, increased humus content, elongation of the humus horizon, and the presence of deep gley.

Based on the type of water regime and the degree of severity of hydromorphism, soils are divided into subtypes: meadow-chernozem and meadow-chernozem.

Meadow-chernozem soils are formed as a result of increased temporary surface moisture with deep groundwater (4...7 m). The profile has the following structure: A - humus-accumulative horizon, black or dark gray, granular, loose, with increased thickness compared to chernozems, contains a lot of roots and molehills; the transition is gradual; AB - lower humus horizon, dark gray with a brownish tint, granular or lumpy-granular, loose, contains many plant roots, molehills, sometimes pseudomycelia of carbonates are observed in the lower part. The total thickness of horizons A + AB ranges from 50...80 to 100...120 cm; B - heterogeneously colored (brown with a large number of dark gray, brown-gray humus streaks in the form of tongues to a depth of 100... 150 cm) transitional horizon, nutty and prismatic-nutty, may contain carbonates in the form of pseudomycelium, molehills, plant roots; S k is a soil-forming rock of yellow-brown and fawn color, pseudomycelia and carbonate deposits are found, and rusty-ocher spots are observed from a depth of 2...3 m.

Soils are divided into types based on thickness, humus content and accompanying processes, such as chernozems.

Due to the warm and mild climate, southern European chernozems (Moldova, southern Ukraine, Ciscaucasia) are characterized by intense biological circulation, extensive digging of the profile as a result of the activity of earthworms, and periodic washing of the profile. These soils are distinguished by a large thickness of the humus horizon with a low humus content (less than 8%), the absence of easily soluble salts and gypsum, and abundant carbonate in the form of deposits, cobwebs, veins, etc. in the upper horizons and micellar forms in the lower ones. Micellar forms of carbonates indicate their migration and seasonal pulsation in soils. These soils are called "micellar-carbonate".

In the chernozems of the Eastern European group, due to the drier and colder climate, the thickness of the humus horizon is less, and there is more humus (7...12%); the profile is washed from easily soluble salts only in the forest-steppe, while in the steppes at a depth below 2 m new formations of gypsum are observed.

The chernozems of Western Siberia are characterized by deep flows of humus along cracks formed when the soil freezes, a high humus content (up to 10...14%) with a rapid decrease in its amount with depth, as well as the presence of gypsum in the steppe part.

In Eastern Siberia, the biological cycle of elements is significantly suppressed by low temperatures, therefore the humus content in them is low (4...9%), the thickness of the humus horizon is insignificant. These soils are often called low-carbonate or no-carbonate soils because they contain little or no carbonate (powdery).

The granulometric composition of soils depends on the parent rocks and varies from sandy loam to clayey, but loamy varieties dominate.

Chernozems are characterized by the absence of noticeable changes in granulometric composition during soil formation. Only in podzolized and leached chernozems is there an increase in the amount of fine dust fraction down the profile. In all soils, compared to the parent rock, the profile is enriched in silt. The composition of the silt of southern European chernozems is dominated by the montmorillonite group, hydromicas contain less than 25%, and kaolinite is not observed. Eastern European chernozems are dominated by hydromica minerals and hydromica-montmorillonite mixed-layer formations. Minerals of the kaolinite and chlorite type are present in very small quantities. The micromorphology of clay matter is closely related to the depth of carbonates in the profile. In soils in which the carbonate horizon follows the humus horizon, the clay matter is coagulated with humus and fixed. The subsidence of the carbonate horizon entails peptization of the clay and some movement of it along the profile.

Chernozems are characterized by looseness, high moisture capacity, and good water permeability. The structural composition of virgin chernozems is dominated by water-resistant granular aggregates, which is especially pronounced in typical, leached and ordinary chernozems. Podzolized and southern chernozems contain fewer water-stable aggregates. When using chernozems in agriculture there is a decrease in the content of lumpy-granular, granular, dusty fractions, a decrease in water resistance and a decrease in the size of structural units.

Chernozems are characterized by a high humus content in the humus-accumulative horizon A, which gradually decreases with depth, with the exception of the soils of Eastern Siberia (table). The amount of humus in chernozems ranges from 3...5% (reserves are 270...300 t/ha) in the southern to 5...8% (450...600 t/ha) in typical southern European groups, from 4 ...7% (300...450 t/ha) in the southern ones to 8...12% (600...750 t/ha) in typical Eastern European ones, from 4...6% (200... 300 t/ha) in the southern to 10...12% (450...500 t/ha) in typical Western Siberia, from 3.5...5.0% in the southern to 5...7% ( 200...300 t/ha) in leached Eastern Siberia. The composition of humus in horizons A and AB is dominated by black humic acids associated with calcium. The amount of humic acids associated with R2O3 and the clay fraction is insignificant. Ratio Stk: Sfk = 1.5...2.6. In chernozems, compared to other soils, fulvic acids are the lightest, with the lowest optical density and a low content of the aggressive fraction.

The soil reaction is slightly acidic or close to neutral in the humus horizons of leached and podzolized chernozems, or neutral and slightly alkaline in chernozems of other subtypes. In the lower horizons, the soil reaction is predominantly slightly alkaline, less often alkaline.

Zone	Chernozem	Humus content, %	Humus reserve, t/ha
South part Europe	Southern	3...5	270..	.300
	Typical	3...8	450..	.600
Eastern part of Europe	Southern	4...7	300..	.450
	Typical	8...12	600..	.750
Western Siberia	Southern	4...6	200..	.300
	Typical	10...12	450..	.500
Eastern Siberia	Southern	3,5...5	200..	.250
	Leached	5...7	200..	.300

Chernozems have a high absorption capacity (50...70 mg equiv/100 g of soil for loamy varieties), significant saturation of the absorption complex with bases, and high buffering capacity. The composition of exchangeable cations is dominated by calcium, then magnesium (15-20% of the total). In podzolized and leached chernozems, hydrogen is present in the absorbing complex. In ordinary and southern chernozems, in addition to calcium, sodium is present in the absorbed cations, and the magnesium content increases.

The soils are characterized by a significant gross content of nutrients. For example, in typical heavy loamy chernozems the amount of nitrogen reaches 0.4...0.5% (10...15 t/ha), phosphorus - 0.15...0.35%. The content of mobile forms of nutrients depends on the climate, agricultural practices and cultivated crops. Largest quantity they are contained in the arable layer of cultivated chernozems.

Chernozem is rightfully considered the most fertile type of soil. It is being formed naturally in certain climatic conditions. This is soil saturated with humus (a product of rotting plant remains). It has a granular-lumpy structure and black color.

Thanks to its qualities, chernozem is highly valued by farmers, cultivators and gardeners. It is perfect for growing fruit crops, cereals, flowers. Trees and bushes grow well on it. In Russia, most chernozem soil types are found in Western Siberia, the North Caucasus, and the Volga region.

1 How is black soil formed?

Why are chernozems the most fertile of all types of soil? The secret of their superiority lies in the peculiarities of soil formation. There are three main factors influencing the maturation of “black gold”:

• climatic;
• biological;
• geological.

Russian chernozem is formed in steppe and forest-steppe climatic zones. In addition to climate, vegetation plays a large role in the formation of this type of soil. In the process of its decay, humus is formed - humus - which is considered the main criterion of fertility.

Another important factor in the formation of chernozem is groundwater. Plant roots absorb useful trace elements and minerals from groundwater. Having received the necessary substances, root system penetrates the soil, which helps loosen the soil. Loose soil facilitates the passage of air masses.

live in the soil different types microorganisms that also play a positive role in the formation of “black gold”: they help loosen the earth and participate in the processing of vegetation residues. However, for planting flowers and other plants with a poorly developed root system, chernozem is a dense soil, so it needs to be diluted.

1.1 Classification of chernozems

Depending on the conditions of formation, the type of chernozem soil can be divided into several subtypes:

1. Podzolized.
2. Leached.
3. Typical.
4. Ordinary.
5. Southern.

Podzolized chernozems develop under broad-leaved forests of the forest-steppe zone. Due to the humidity of the climate, such processes as leaching (dissolution and washing away of salts in the soil with water) and podzolization (removal from upper parts soil clay particles, aluminum and iron oxides, etc., which leads to a decrease in fertility). Podzolized soil is widely used in agriculture for growing grain, vegetable and fruit crops.

Leached chernozems are formed under forb-grass vegetation. In its properties, this type is similar to the type of podzolized chernozems with the exception of some characteristics.

Typical chernozems have best qualities, inherent this species soil They form under forb-grass vegetation in the southern subzone of the forest-steppe zone. The humus content in the soil of this subtype is high and sometimes reaches 15%.

Ordinary chernozems are common in some parts of the steppe zone. They formed under forb-fescue-feather grass vegetation. They have a smaller layer of humus compared to typical chernozems.

The southern subtype of chernozems was formed under fescue-feather grass vegetation in the southern part of the steppe zone. The humus content reaches 4-7%. Under the humus layer there is a carbonate layer in the form of white-eye.

Based on thickness and humus content, chernozems are divided into 4 groups, the presence of which is typical for certain territories.

The Southern European group of chernozem soils is distributed in the territory of Moldova, Southern Ukraine and Ciscaucasia. They are characterized by a large thickness of the humus layer with a low humus content, abundant carbonate in the form of cobwebs, veins, etc.

The Eastern European group includes chernozem soils of the European territory of Russia. A colder and drier climate caused the formation of a less powerful humus horizon with high content humus.

The group of Western and Central Siberian chernozems is located on the territory of Western and Central Siberia, as well as Kazakhstan. This group is characterized by deep flows of humus through cracks that form in the ground due to soil freezing, as well as a high concentration of humus with a sharp decrease with depth.

The East Siberian group occupies the territory of the Transbaikal steppes. Due to low temperatures, biological circulation here is at an insignificant level. This caused the formation of a small humus layer. The humus content in it is also low.

2 Purchase of black soil

Chernozem is the most fertile soil in the world. This is influenced by the composition of the soil and the amount of organic matter in it. However, when purchasing such soil, you need to keep in mind that in an unnatural environment, over time it loses those qualities for which it is so valued. But if you decide to increase the level and quality of fertility, improve the characteristics of the soil on your site, chernozem soil is perfect for this purpose.

So how to choose this product? And what should you be guided by in your choice? We advise you to pay attention to several factors.

2.1 Territory of soil formation

The composition and characteristics of chernozem depend on this factor. Therefore, before purchasing, you need to ask where it was brought from. The difference in soil composition directly depends on the area of ​​its formation. Therefore, taking this detail into account will help you make a better choice.

2.2 Soil composition

Chernozem soil should be saturated with all essential microelements. Of course, it is best to detect their presence using agrochemical analysis in the laboratory. But you can learn something without help special devices. There are some tips that will teach you how to choose this type of soil correctly.

Chernozem is highly saturated with potassium. Potassium-poor sandy loam and sandy soils, where there is sand at a depth of 20-30 cm under the chernozem. Therefore, if you notice the presence of sand in the soil, then this soil will be of low quality.

You can lightly rake the ground. It should be dry on top, but at a depth of about 20 cm it will be moist and crumbly. This is a good sign. You can also wet a lump of soil and make a circle out of it. If it crumbles, this indicates a low humus content.

2.3 How to determine black soil (video)

2.4 How much does black soil weigh?

Before purchasing, you should find out how many kilograms 1 cubic meter of chernozem soil weighs. The question is quite complex, since the weight depends on its condition and humidity. On average, the weight of 1 cubic meter of chernozem ranges from 1000 to 1200 kg.

2.5 Price

Of course, a very important question is how much Russian black soil costs. When purchasing soil, you should pay attention to what factors affect its cost. This may include the place of soil formation, as well as the location of the customer.

In addition, the price will depend on the supplier. For example, the price of such soil per cubic meter in Moscow and the Moscow region can be in the range of 1110-1500 rubles per cubic meter. The price per cubic meter depends on the set of soil qualities. If you want to purchase black soil in bags, its cost will be from 350 rubles per bag. Chernozem in bags is very convenient for transportation and storage.

For more detailed information, it is better for you to contact qualified specialists. In Russia, many companies deliver this type of soil. Therefore, it will not be difficult for you to find a supplier on the most favorable terms for you.

Chernozem is one of the most fertile soil types. This is a kind of separate ecosystem, widely used in all regions of our country. That is why it would be useful for gardeners to know what black soil is, what characteristics it has and how it differs from other types of soil.

Chernozem is created only by nature. It is impossible to make artificial black soil using various fertilizers. It is formed in natural areas where a temperate continental climate prevails. The place of formation of chernozem is loess-like loams or clays, loess. The necessary conditions for its formation: periodic changes in humidity and temperature, suitability of the soil for the life of microorganisms and invertebrate creatures, abundant and perennial herbaceous vegetation. But nowadays you can buy black soil in the Moscow region with the soil delivered to any region of Russia, which expands the opportunities for summer residents to improve the soil on their personal plot.

Characteristics of chernozem

The main characteristics of this soil include:

• lumpy structure (the soil “breathes” and allows moisture to pass through);
• high humus content (the soil does not have time to deplete quickly);
• high percentage of calcium content (it is necessary for absolutely all plants);
• balance and easy availability of microelements useful for plants (iron, nitrogen compounds, phosphorus, sulfur);
• neutral or near-neutral acid-base reaction (suitable for a larger number of plants);
• as a consequence of all of the above - the high fertility of these soils.

There are five main varieties of this soil:

• ordinary chernozem (have a more lumpy structure, good moisture holding capacity);
• southern (with the highest humus content);
• typical (has the most striking basic characteristics of such soils, the most balanced chernozem);
• podzolized (has a slightly acidic reaction and a small supply of humus);
• leached (contain a lot of calcium and magnesium).

Distinctive features of chernozem

What are the differences between manure, humus and peat from black soil? Manure is the waste of animals and birds. Humus is formed from manure due to its overheating and processing by worms, insects and microorganisms for a long time. Chernozem is initially a fertile layer of soil, and humus and manure can be called fertilizers to increase its fertility.

Peat, like chernozem, is formed due to the decomposition of plant remains. But this decomposition occurs in marshy areas, and its main plant component is moss. For these reasons, chernozem can retain moisture, but peat cannot.

Real, undiluted chernozem has a rich black color and a coarse-grained or lumpy structure. If you wet it, its properties will resemble clay: the same consistency and a long drying process.

A distinctive feature of this soil is a greasy mark on the hand after squeezing a lump of black soil. This is due to the high percentage of humus content in it.

People who have a dacha or their own vegetable garden know that better than black soil no soil to be found. It contains a lot of humus and nutrients. However, many people forget that everything loses its properties over time. And even black soil will sooner or later have to be “fed” with fertilizers.

Fertilize vegetables and flower crops chernozem is not recommended. Their root system is too weak, so the soil may soon become compacted, which means the air and water permeability of the chernozem will drop sharply.

Most often, summer residents use a mixture of black soil, peat and simple garden soil. Decorative perennials they get along well in the soil with chernozem added to it; it is also often used when planting plants in greenhouses and greenhouses.

Chernozem is dug up only with a pitchfork to maintain its density. To restore the acid-base balance, add lime or wood ash, and in weakly alkaline - fertilizers with high acidity.

The first scientific provisions on the origin of chernozem are in the works of M.V. Lomonosov (mid-18th century), who believed that these soils were formed as a result of the decomposition of plant and animal organisms. At the end of the 18th - beginning of the 19th centuries. P. Pallas et al. put forward a hypothesis of the marine origin of chernozem and considered it as marine silt remaining after the retreat of the Caspian and Black Seas. This hypothesis only has historical meaning; it reflects the concept of soil as a geological formation that existed at that time. The hypothesis of the swamp origin of chernozem also turned out to be untenable. Its supporters (E.I. Eichwald and others, mid-19th century) believed that in the past the zone of chernozem soils was tundra, heavily swamped spaces; The decomposition of swamp vegetation under the conditions of the subsequently established warm climate led to the formation of chernozem. The theory of the plant-terrestrial origin of chernozem (F.I. Ruprecht, V.V. Dokuchaev, etc.) connects their formation with the settlement and development of meadow-steppe and steppe herbaceous vegetation. This theory is most fully presented in the work of V.V. Dokuchaev “Russian Chernozem” (1883), which proved that chernozem was formed as a result of the close interaction of herbaceous vegetation, climate, terrain, parent rock and other soil-forming factors; the consequence of this process is the accumulation of humus.

Herbaceous vegetation annually leaves a large amount of litter in the soil - plant residues, 75-85% of which are roots. The hydrothermal conditions of the steppe and forest-steppe zones favor the humification process, which results in the formation of complex humic compounds (mainly humic acids), which give the soil profile a dark color. The best conditions for the humification process are created in spring and early summer. At this time, there is a sufficient supply of moisture in the soil from autumn-winter precipitation and snowmelt, which is favorable temperature regime. During the period of summer drying, microbiological processes noticeably weaken, which protects humic substances from rapid mineralization. During the decomposition of plant residues rich in ash elements and nitrogen, bases are formed (especially a lot of calcium), which saturate humic substances. This contributes to their fixation in the soil in the form of humates and the preservation of a neutral or close to it reaction in the upper horizons of chernozem.

Chernozem formation occurs most intensively in the forest-steppe zone, where better moisture promotes more powerful development of herbaceous vegetation and active humification of its remains. In the steppe zone, insufficient moisture determines a shallower depth of root penetration, a decrease in the amount of litter entering the soil, and its more complete decomposition.

2. Types of black soil

Chernozem is divided into two gradations: according to the thickness of the humus layer and according to the humus content. Let's look at each gradation in more detail.

According to the thickness of the humus layer, chernozem is divided into:

· heavy-duty (thickness more than 120 cm);

· powerful (120 – 80 cm);

· medium-power (80 – 40 cm);

· low-power (less than 40 cm).

· obese (more than 9%) – black in color;

· medium humus (6 – 9%) – black color;

· low humus (6 – 4%) – dark gray color;

· low humus (less than 4%) – gray color;

· microhumus (less than 2%) – light gray color.

According to the type of chernozem there are:

· podzolized chernozems;

· leached chernozems;

· typical chernozems;

· ordinary chernozems;

· southern chernozems.

There are also mycelial-carbonate chernozems (Azov and Ciscaucasia), which are formed in areas with warm winters (the soil does not freeze), and chernozems that develop under conditions of winter freezing. Depending on the salinity, ordinary, carbonate, solonetsic, solonetzic-solonchakous and others are distinguished.

3. Layers of black soil

As mentioned above, chernozem can be divided into several types - layers: depending on the thickness of the humus layer (A and B1) - low-thick (less than 40 cm), medium-thick (40-80 cm), powerful (80-120 cm) and heavy-duty (more than 120 cm). We present the characteristics of the chernozem layers in the form of a summary table (Table 1).

Table 1 - Comparative characteristics layers of black soil

4. Properties of chernozem

Chernozems have good water-air properties, are distinguished by a lumpy or granular structure, a content of calcium in the soil absorption complex from 70 to 90%, a neutral or almost neutral reaction, increased natural fertility, intense humification and a high, about 15%, content in upper layers humus.

Chernozem has the largest amount of humus in its composition, which determines its high fertile properties. Chernozem also contains a large number of other useful substances, necessary for plants: nitrogen, sulfur, phosphorus, iron. Chernozem has a dense, lumpy structure; the most fertile southern chernozem is even called “fat.”

Because of its fertility, black soil has always been highly valued throughout the world. And now the black soil - best view soil for growing vegetables, fruits, berries. For some plants, peat, sand or compost should be mixed into the chernozem to loosen the soil, since chernozem itself is not very loose.

5. Areas of distribution

The area of ​​chernozems on the globe is about 240 million hectares. They are confined to Eurasia, Northern and South America. In Eurasia, the black earth zone (the largest) covers Western and South-Eastern Europe (Hungary, Bulgaria, Austria, Czech Republic, Yugoslavia, Romania), extending in a wide strip to Russian Federation and continues in Mongolia and China. IN North America chernozems occupy some states of the Western United States and the southern provinces of Canada; in South America they are located in the south of Argentina and in the southern foothills of Chile.

In Russia, chernozems are common in the central regions, the North Caucasus, the Volga region and Western Siberia. Very fertile and almost completely plowed. The black soil zone is the most important agricultural region, in which more than 50% (130 million hectares) of arable land in our country is located. Winter and spring wheat, sugar beets, sunflowers, flax, buckwheat, and beans are grown here; livestock farming, fruit growing, vegetable growing and viticulture are developed.

6. Application of black soil

Chernozem is ideal for any type of planting. It does not require additional processing and the use of organic and mineral fertilizers. In conditions of good moisture, chernozem is very fertile - it can be used for growing grain, vegetable and fodder crops, for growing gardens and vineyards, for landscaping work in landscape design.

Most often, chernozem is used to form a certain reserve of soil fertility. The addition of chernozem to even the most depleted soil leads to its improvement, restoration of all its characteristics, especially water permeability, and enrichment with nutrients. A particularly significant effect is noticeable when using chernozem on light sandy and sandy loam soils.

Chernozem can be used separately or as part of soil mixtures. It should be said that a single use of chernozem on a site does not solve the problem of fertility once and for all. Over time, the microbiological composition of the soil changes, and at the same time the content of nutrients decreases.

1. Akhtyrtsev B.P., Akhtyrtsev A.B. Soil cover of the Central Russian Black Earth Region. Ed. Voronezh University, 1993

2. Aderikhin P.G. Soils, their genesis, properties and brief agricultural characteristics. Ed. Voronezh University, 1993

3. Akhtyrtsev B.P., Efanova E.V. Humus of subtypes of Central Russian chernozems of different granulometric composition. Ed. VSU, 1999

5. Orlov D.S. Soil chemistry. M.: Publishing house. Moscow un-ta. 1992.

6. Shcheglov D.I. Chernozems of the center of the Russian Plain and their evolution under the influence of natural anthropogenic factors. Ed. "Science", Russian Academy of Sciences, 1999.

Aderikhin P.G. Soils, their genesis, properties and brief agricultural characteristics. Ed. Voronezh University, 1993

Shcheglov D.I. Chernozems of the center of the Russian Plain and their evolution under the influence of natural anthropogenic factors. Ed. "Science", Russian Academy of Sciences, 1999.

Glazovskaya M. A., Soils of the world, parts 1-2, M., 2002-73.

Orlov D.S. Soil chemistry. M.: Publishing house. Moscow un-ta. 1992.

Akhtyrtsev B.P., Efanova E.V. Humus of subtypes of Central Russian chernozems of different granulometric composition. Ed. VSU, 1999

Glazovskaya M. A., Soils of the world, parts 1-2, M., 2002-73.

Akhtyrtsev B.P., Akhtyrtsev A.B. Soil cover of the Central Russian Black Earth Region. Ed. Voronezh University, 1993

Chernozems develop in the steppe zone. Chernozems can and do appear on any rocks (on granites in Ukraine, on basalts in Transcaucasia), but loess-like rocks contribute most to the formation of chernozems.

The nature of the parent rock affects the soil and, along with the relief, for example, determines the emergence of different soil varieties. However, the direction of soil formation remains the same - evidence that soil formation in this case is regulated by some more general reason. This common cause is climate and vegetation patterns.

The climate in the steppes is dry. This is caused by both the small (400-500 mm) amount of precipitation and the fact that it falls mainly in the summer, when temperatures are high and, therefore, evaporation is high. A number of conclusions can be drawn from this fact:

1. Since there is little moisture, the soil should be lightly washed. This should lead to a weak division of the soil profile into horizons, to the richness of the soil in bases (which are almost not carried out of it) and to the fact that only easily soluble substances will be carried from the upper horizons to the lower ones.

2. In the steppes, only herbaceous vegetation develops, but since it dies off annually, a very large amount of organic matter enters the soil annually, both in the form of the remains of above-ground parts of plants and in the form of the remains of their dense root system.

3. Mineralization of organic matter should be weak. In summer, the soil dries out; in winter, unless the snow cover is thick enough, it freezes. Consequently, during the winter, biochemical processes sharply slow down or stop. High summer temperatures favor the activity of microorganisms that decompose organic matter, but lack of moisture inhibits their activity. As a result, organic residues cannot be completely decomposed, products of incomplete decomposition accumulate and, therefore, the soil must be rich in humus.

4. The parent rock (loess) contains many salts, especially calcium carbonates. Therefore, the soil solution is rich in electrolytes, and the absorbing complex is saturated with calcium. Under these conditions, colloids must be in a collapsed state. The consequences of this fact are twofold: soil particles bind into aggregates, forming a strong granular (with grain diameter not exceeding several millimeters) structure, very favorable for water and air regime soil; The formation of the structure is also helped by a dense network of roots that divide the soil into small lumps. In addition, coagulated organic colloids saturated with calcium are known to be difficult to destroy (disperse) even in the presence large quantity water, i.e., they become slightly mobile, and thus humic substances, protected from the destructive action of water and from removal from the soil, accumulate. In other words, the accumulation of humus in chernozems should be facilitated not only by the slow biochemical decomposition of organic matter, which occurs only in the spring, when there is enough moisture in the soil, but also by the properties of the rock itself, which contains many electrolytes, including such an energetic coagulator as calcium ion.

All the characteristics described above are indeed inherent in typical chernozem. Two main horizons can be distinguished in it: humus and carbonate. The humus horizon is dark, almost black, as it contains 4-18% humus; it is eluvial-accumulative (because humus accumulates in it, and simple salts and solutions of some organic substances are carried away) and is divided into subhorizons A and B 1. An indicator of the weakness of the eluvial process is that the composition of the soil changes relatively little over the horizons, only in the lower horizons is a noticeable accumulation of carbonates detected.

The thickness of the black subhorizon A, which has a well-defined granular structure, is 50 centimeters or more. Horizon B 1 (50-70 cm thick) has almost the same color, but under the influence of the HCl solution it boils in its lower part, thereby indicating that the carbonates have not been completely washed out of it. The gray-fawn horizon B 2 (40-60 cm thick) boils very violently, and the release of calcium carbonates in the form of white specks is very abundant here. All the described horizons contain humic substances, and a change in their color indicates a decrease in humus content from top to bottom. The parent rock for typical chernozem is loess.

Due to heterogeneity natural conditions There are many varieties of chernozems in the steppe zone. The drier the climate, the less humus there is in chernozems; in addition, the thickness of the A horizon changes, the degree of soil leaching, etc. Without going into consideration of all these varieties here, we only note that typical chernozems, according to their humus content, are divided into fat (humus more than 10%), ordinary (6- 10%) and southern (4-6%). These subtypes in turn; According to the thickness of the humus horizon, each is divided into powerful (more than 80 cm), medium-thick (50-80 cm) and low-thick (less than 50 cm).

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