Chernozem is a natural wealth. It improves the quality of the soil that is used to grow crops. This material contains humus, which is responsible for fertility. Chernozem includes humus and carbonate profiles. It is formed due to the sod process, as well as complex biochemical reactions.

General information about chernozem, its types, structure

Natural material may be intact or plowed. The sod process occurring in the chernozem involves the accumulation of humus with the inclusion of humate and calcium. Natural wealth contains mineral components necessary for plant photosynthesis, among them:

• iron;
• calcium;
• magnesium.

The structure of the chernozem is lumpy or granular. It is caused by the influence of living organisms, products of their vital activity. Natural material is rich in organic matter, which is also responsible for fertility. The weakening of the sod process is associated with plowing. When performing this procedure, the natural structure of the earth is disturbed, humus is lost.

In the chernozem, carbonates migrate and accumulate. If the carbonate migration proceeds correctly, the earth is saturated with calcium, acquires a neutral alkaline reaction. Migration of carbonate is needed for heat and air exchanges. The forest-steppe chernozem is washed by water, the steppe chernozem receives less moisture. In the latter case, carbonate migration is slowed down, but still the soil receives water.

Description of brown soil

There are such types of brown soil:

• typical;
• carbonate;
• leached.

The latter is formed in forest areas. Leached soil is available on the territory of Russia, Europe, North America. It is suitable for trees and large shrubs. Alkaline soil contains little clay. Carbonate in such land is pronounced. The reaction, as a rule, is slightly alkaline, the pH level is 7 - 7.2. The most popular of the carbonate soils are chestnut and grey-brown. They are distinguished by a dull yellow-brown tint. The pH level is 7.5 - 8.

If a lot of carbonate accumulates in the soil, the surface acquires a light marble color. Certain biochemical reactions take place in the soil. Water washes away salt and carbonates. Humus is a fertile layer. In addition to it, clay is present in the soil, a small amount of iron hydroxide. Under natural conditions, the earth receives not so little water, because of this, natural reactions proceed slowly, a small amount of clay is formed. The formation of brown soil is impossible without rubification. This process is responsible for the shade. Iron oxide is weathered, dehydration occurs, resulting in a microscopic film on the soil. Brown soil is available in coniferous and deciduous forests.

About gray forest soils

They are common in Russia, Europe, America, Canada. The soil of the forest-steppe has a complex composition. It combines several soil mixtures. Soil of this type is washed. The forest-steppe zone has a temperate continental climate, cool and humid summers. In such conditions it is possible to cultivate agricultural plants.

Gray forest soil is found in the forest-steppe zone of Europe, birch forests of Siberia. On the territory of America, there is an alternation: deciduous forests are combined with the steppe. Gray forest soils are distributed throughout the globe. They are rich in aluminum, iron and phosphorus. Useful properties are also due to the content of magnesium, hydromica. There are two types of soil for agricultural purposes: developed and cultivated.

Chernozem in agriculture

Natural material can be called perfect. It is rain and drought tolerant. Chernozem will not replace organics or any mineral compositions. The soil used in agriculture has been formed for several thousand years. Chernozem ordinary exists in conditions of different climates. The peculiarity of natural material is that it contains humus, which is responsible for fertility.

Fertile soil has a lumpy or granular structure. It contains 40-65% calcium. Red chernozem is rich in acids. They, together with microorganisms, penetrate the root system of the plant and provide deep nutrition. The soil used in agriculture is well permeable to water, however, it is not very loose. To improve the composition of the soil, you can add a small amount of peat. This component will retain water, so the plants will get moisture longer. Fertile soil consists of several parts of black soil, one part of sand and peat.

If the soil is fertile, it leaves a characteristic imprint when squeezed in the hand. Such land contains a lot of humus and is suitable for growing various crops. Sandy soil has a porous structure, clay soil is heavy. Plants take root well in soil saturated with humus. This component is responsible not only for fertility, but also for air exchange. Having black soil on the site, you can forget about chemicals for a while.

Fertile land properties

Speaking of chernozems, it must be remembered that after a while valuable substances evaporate. To make up for the shortage, it is necessary to use organic matter or chemicals. The stale soil is a little pale. A certain amount of valuable substances, including humus, is washed out with water. The roots also absorb valuable components. Microorganisms that live in fertile soil die over time. They are needed for all natural reactions to take place. If the soil becomes scarce, the gardener gets a poor harvest. After 3-4 years, the land becomes less fertile.

If crops are planted in the garden that have a small root system, the soil will deteriorate faster. Trees and large shrubs loosen the ground, which means that they improve air circulation. Thanks to trees and shrubs, the soil is divided into several sectors. Gardeners who grow small plants run the risk of getting a heavy substrate after a couple of years.

Chernozem is needed for the growth of large and medium plants. If crops with weak roots are grown on the site, it is worth improving the composition of the soil by adding a small amount of black soil. For vegetables, a soil mixture consisting of garden soil and black soil in proportions of 3: 1 is ideal. If the soil has a neutral pH, acidifying compounds should be added. They include ammonium.

• compost;
• manure;
• organic fertilizers.

Useful minerals. Green manure or auxiliary plants also increase the fertility of the soil. They are grown once every five years, embedded directly into the ground. If the soil has a low pH, such as 5, deacidification is required. For these purposes, use. Make 200 g per 1 sq. m. If there is little magnesium in the soil, dolomite flour must be used. Make 200 g per 1 sq. m.

If possible, use soil that has normal acidity. The optimum pH level should be within 7. You can buy indicator paper. It will allow you to determine the acidity of the soil in a particular area. Chernozem contains humus. This substance is formed naturally when plant residues rot. If the fertile soil has a large amount of humus, a good harvest is guaranteed.

Widespread use of chernozem

Natural material can be added even to depleted soil. It has a healing effect.

1. When cultivating horticultural crops, it is not recommended to dig into the ground with a shovel. It is better to use a pitchfork, otherwise the ground will become very dense.
2. Do not destroy earthworms. They loosen the soil and promote formation. By properties, this natural material is compared with humus.

How to choose the right thing to pay attention to?

Gardeners are interested in how to choose black soil and not fall for the trick of scammers. There are different reviews about black soil on the network, among them are not only positive, but also negative. Summer residents claim that they bought poor-quality soil mixture instead of the declared black soil. To avoid mistakes, you need to contact trusted specialists. Chernozem cannot be cheap. It is brought from the territory where there are natural deposits. The seller spends a certain amount of money on shipping.

The buyer should contact a well-known manufacturer. A product purchased on the side of the road is likely to be of poor quality. Good black soil improves soil properties. It makes up for the lack of trace elements necessary for the full photosynthesis of the plant. As noted, over a certain time, the black soil loses its properties.

What do scammers do

1. An unscrupulous manufacturer can sell a soil mixture of soil, sand and peat. She is of no use.
2. Most buyers "peck" at a low cost. Dried silt resembles black soil. It lies in the depths of the lake and is not used in agriculture. Fraudsters can give out silt for black soil. When exposed to moisture, the sludge becomes acidic and becomes covered with a characteristic crust.
3. An unscrupulous producer can sell black soil, which contains a lot of chemicals. It is mined in the fields where there was previously agricultural work.
4. In fact, ordinary land located near the highway can be taken as black soil. It contains heavy metals and can harm the plant.

Before buying black soil, you need to check the documentation. If the seller provides a certificate received in the environmental register, then the product has passed the test. The buyer should know the chemical and physical properties of the soil. The first appear in the documents. The certificate indicates the amount of nutrients, including humus. Such a document indicates what the black soil consists of. Quality soil contains a lot of nitrogen and potassium. These components are necessary for the full photosynthesis of plants. There is little nitrogen in sandy and sandy soil.

It is recommended to carefully examine the ground. It should not contain sand and other third-party impurities. To check the physical properties of the earth, you need to hold it in your hands. It's best to inspect the item. The top layer may be dry, but at a depth of 20 cm - wet. High-quality black soil has a rich black color and a crumbly structure. You should take a small amount of earth and moisten. If it crumbles, then there is little humus. The structure of the earth must be homogeneous. It is not recommended to buy black soil with the inclusion of sawdust, twigs, foliage.

Fertilizers for depleted soil

Now we know what black soil is and what properties it has. Over time, it becomes less loose and fertile.

1. Ash is used to make up for the lack of valuable substances. It is rich in manganese, boron, lime. Most summer residents use the ashes of deciduous crops. This fertilizer contains more valuable substances. The ash of young trees saturates the soil with nitrogen, which is necessary for the healthy development of the root system. The fertilizer does not contain chlorine - this is an important advantage.
2. To improve the composition of the soil, you can use manure. It promotes the growth of fruit crops. Gardeners often use rotted manure. It is applied once every 3 years. Bird droppings are also used as fertilizer. Lay in a layer of 15 cm and sprinkle with superphosphate. Manure can be diluted with peat or ordinary fertile soil.
3. To improve the quality of the soil, you need to make a pile of compost. It includes rotted grass, weeds, food debris. In order for the fertilizer to show its properties to the fullest, it is necessary to moisten it. You can lay weed grass between rows of shrubs. It will decompose and saturate the soil with valuable components. The remains of plants are also buried in the ground, after which they are dug up.

Mineral compositions

To improve the quality of the soil, mineral and organic agents are used. The first allow you to get a rich harvest. The latter saturate the soil with nitrogen, as well as valuable trace elements.

There are several types of mineral compositions. Each of them improves the quality of the soil and contributes to the good growth of seedlings.

1. Phosphate fertilizers include superphosphate. This substance is embedded in the soil during digging, previously poured with water. When using superphosphate, you must follow the instructions. Fertilizer is not mixed with chalk or lime. Instead of superphosphate, phosphate rock can be used.
2. Potassium sulfate is applied in the fall, after liming. The fertilizer contains wood ash, which regulates the acidity of the soil. The potassium composition is rich in phosphorus, iron, silicon. The drug of this group is applied in spring or autumn. Potassium chloride is saturated with chlorine, which can harm plants. The agent is applied moderately, clearly following the instructions. Well, if the excess chlorine is washed out by groundwater.
3. Nitrogen fertilizer is used as root dressing. Compositions of this type have an acidifying effect. Nitrogen is contained in carbonite. If necessary, use sodium nitrate.

The soil is fertilized with green manure. Auxiliary crops make up for the lack of valuable substances and nitrogen. When used correctly, green manure will suppress weeds. You should grow plants that are rapidly gaining green mass. They are buried a couple of centimeters or left on the surface of the soil. Green manure protects the soil from pests. Gradually, the roots rot and the soil receives the necessary amount of valuable substances. Green manure is often used as a fertilizer, mowed mainly before flowering.

To grow a stronger plant, you need to follow the rules of agricultural technology. When choosing black soil, you should be extremely careful. In the fall, digging is done. Thanks to this procedure, the roots receive more oxygen and air exchange improves. It is advisable to dig up the ground when the air temperature reaches + 13 degrees. It is not recommended to overmoisten the ground, water should be applied moderately, immediately after the procedure. Digging is very necessary if the soil is clayey. When carrying out the procedure, it is important not to damage the roots. To keep the soil loose longer, use a fork.

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Material prepared by: Yuri Zelikovich, teacher of the Department of Geoecology and Nature Management

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Chernozem is famous not only for its phenomenal fertility; loess, red and red-brown soils of humid subtropics and tropics are almost as productive. An equally important advantage of chernozem is its stability as a soil ecosystem. Chernozem, under favorable conditions and with proper use, can withstand monoculture for decades without visible signs of depletion; recultivated relatively quickly and inexpensively. Other types of highly productive soils require quite complex and expensive agricultural techniques, irrigation/reclamation to maintain fertility, and/or take a long time to recover from depletion, or are depleted irrevocably if misused. The latter in ancient times more than once led to the death of entire, highly developed civilizations for that time (for example, the Indus and Oxo-Bactrian), and the black soils that were then are still there.

Chernozem soil in the world occupies a small part of the land area (see map of soils of the world), and in the Southern Hemisphere there is no chernozem at all.

Of the world reserves of chernozem, the Russian Federation owns 52%, if we count in terms of productivity, or 48% in terms of area. Therefore, the interest of Russian readers in chernozem is quite justified. But dachas on chernozem have never been given, and land on it is very expensive. For this reason, this article aims to:

• First, explain how to rationally use a piece of black soil, if you got it.
• Secondly, is it necessary and in what cases to buy expensive black soil.
• Thirdly, how to deal with soils related to chernozem (which Russia is also by no means poor) in order to fully realize their productive potential. This will increase the marketability of the economy, reduce the cost of its maintenance and will benefit the environment as a whole.

What's in it?

So what is black soil good for? What explains its record low ratio of agricultural costs to productivity and the stability of the latter? The "highlight" of chernozem is its micro, even nanostructure, due to which moisture is well retained. The lowest exchangeable moisture capacity of chernozems in the period after plowing (the so-called marginal field moisture capacity, FPV) is 270-380 mm per 1 m of the humus layer. Chernozem seems dense; clenched in the hand, leaves behind a greasy trail. But in fact, this "dirt" is well permeable to water and air. However, the capillaries of the chernozem are tortuous and not very long, so the evaporation of absorbed moisture from the chernozem is not very intense; in this respect, chernozem is not like a wick, but like felt. Simply put, black earth does not bake under the sun.

The consequence of the optimal structure of chernozems, high FPV and the ability to retain moisture when heated is their close to neutral chemical reaction (pH = 6.5-7.5, depending on the type of chernozem). The consequence of the consequence is a favorable environment for useful soil microfauna and microflora. A consequence of the 3rd order is the accumulation of humus, which contains nutrients for plants in the most easily digestible form. Visible fertility is already the top of the "productivity pyramid".

The pyramid structure is stable. In table. the characteristics of the most common and accessible to private traders types of chernozems are given in comparison with associated soils, from which it can be seen that the score (characterizing soil fertility) in chernozems generally outstrips the accumulation of useful substances in them. That is, plants on the chernozem are fed not only fully, but also rationally, which also helps to increase the profitability of the economy and improve the quality of agricultural products.

However, the base of the pyramid cannot be undermined. With regard to chernozem, this means that deep plowing and, in general, rough methods of mechanical cultivation of the earth are unacceptable. It is possible to point out more than one region where, after the collapse of the USSR, as a result of the desire to squeeze everything out of the ground and as soon as possible, meter-long chernozems completely degraded and a crop of 15 centners per hectare is considered good where previously even 60 centners per hectare was usual. However, we will return to the rational use of black soil in our area.

How is black soil formed?

Fertile chernozem is formed when a number of natural conditions coincide, which is illustrated by the left part of Fig. below; on the right there are shown respectively. soil types. It is chernozems that are obtained if it is maintained:

• Plus year - the average annual average temperature is above 0 (typically +3 - +8).
• Precipitation is within 550-650 mm.
• Small and moderate, up to 25%, excess of evaporation over precipitation.
• The long-term average temperature in July is +20 - +22.
• The parent rock is carbonate: limestone, dolomite.

Such conditions are favorable mainly for the development of herbaceous vegetation; herbage of cereals and legumes prevails. From autumn to spring, they rot, resulting in a kind of natural green manure, and very nutritious: legumes, as you know, are nitrogen fixers, and cereals are fed very sparingly. This is eluvium, the deposition of a source of nutrients on the surface of the soil.

In spring, illuvium begins - the process of penetration of decomposed organic sediments into the soil. With the onset of real heat, due to the excess of evaporation over moisture, organic matter lingers in the upper layer, because. the average annual flow of soil water in this zone is generally directed upwards.

Soil salinization, in addition to a relatively small excess of evaporation over moisture, is also prevented by parent rocks. Limestones and dolomites have significant moisture absorption and give water reluctantly; the salt horizon either does not rise to humus at all, or lingers in the subsurface layer.

It is also very important that soil salts in this case are carbonates. They are known to be weak alkalis, and soil acids - humic and fulvic - are also weak. Both neutralize each other, and as a result, an almost neutral environment is obtained, favorable for the development of beneficial micro-animals and suppressing harmful ones. And soil bacteria, nematodes, worms, springtails, tardigrades and soil mites (which are microscopically small and not at all dangerous bloodsuckers) do not need to be taught how to structure the earth, it is in their genes. In addition, carbonate rocks are rich in microelements, which also saturate the humus layer. This is how black soil is formed.

What types of chernozems you can meet is shown on the left in fig. We will need its right part when it comes to the proper use of black soil. In any chernozem, 3 horizons (layers) are clearly distinguishable: illuvial A, transitional B and parent rock C. In works on soil science, they can be divided into subhorizons and provided with indices, for example, A2B1, etc., but we do not have such subtleties will be needed.

However, you are unlikely to encounter the southern black soil. It stays under monoculture for a long time, but it degrades very quickly, in a few years, but recovers for centuries. In America, this was faced at the beginning of the last century, and in the post-Soviet space, literally before our eyes. The surviving spots of natural southern chernozem in the USA and the Russian Federation are now under protection, they are not given for use, and even more so, they are not allocated for construction.

Chernozem in Russia - documentary

Where to get black earth?

Chernozem for the garden can be obtained in the following ways:

1. Buy;
2. Prepare a substitute;
3. Rehabilitate and properly use what is available;
4. Reclaim used land.

Purchase

Soil is a living formation, and black soil is no exception. Just buying a car or two black soils is possible, but irregular and expensive. The source of chernozem entering the market is mainly land allocated for non-agricultural purposes; their humus layer is a valuable commodity. There is no legal development of chernozem as a mineral; at least it shouldn't be.

Most often, ordinary chernozem from the Voronezh, Kursk and Tula regions and podzolized Ryazan, Lipetsk, etc. go on sale. The score of all types of fresh chernozem for sale is up to 85; stale year - 77-78. It is more profitable to use typical and leached chernozems for local agriculture, and there are almost no natural ones on sale.

However, the purchased black soil will give a tangible increase in productivity for no more than 2-3 years. Cut off from the conditions it needs, the chernozem will perish, the reserves of nutrients in it will be depleted, and the microstructure will be disturbed even faster. It would be more or less rational to add 1/3-1/5 purchased black soil to greenhouse land for vegetable crops, provided that the greenhouse is marketable and generates income; in this case, a relatively small regular purchase of black soil for a greenhouse is most often cost-effective.

Another, perhaps justified, option is a one-time purchase of chernozem as a seed for the regradation and reclamation of the soil used, see below. However, before that, it is necessary to study local conditions and find out if this is possible at all.

Substitutes

The manufacture of chernozem (more precisely, its substitutes, since not all black earth is chernozem) is possible on the basis of low-lying peat (black, dense, viscous), humus or compost. The usual proportion is 1 part of peat (humus, compost) to 3 parts of sand and 10-12 parts of ordinary garden soil. The score of the latter increases from 55-60 to 68-75, but also for 2-3 years. In addition, humus and compost need to be made for 2-4 years, and lowland peat is only slightly cheaper than black soil.

Lowland peat, in principle, can be obtained with your own hands in a nearby swampy hollow, in such places it most often lies no deeper than half a meter. It is only necessary to open the turf and choose high-moor peat (brown, fibrous) quickly so that the water does not have time to fill the hole. However, remember the Law on the Subsoil of the Russian Federation! Individuals in Russia can develop minerals to a depth of up to 5 m without any permits and licenses, but only on their own site! That is, the same hole must be on the land you bought, and the deed of ownership is drawn up in accordance with all the rules. If she, a hole, is on your hard-earned 6 acres in a dacha partnership, then formally you are not the owner, and production will be a violation punishable by law. In addition, you run the risk of being extreme in case of any disruption of the water supply in the vicinity, because. with your excavations of the swamp, at least theoretically, you violate the natural subsoil flow.

Use and regradation

First of all, you need to make sure that you are really on a potential black soil, i.e. that the mainland rock is carbonate. Let's return to the right side of Fig. with types of chernozems: this is done by testing for boiling. From different depths, starting from the surface, after 20-40 cm, soil samples are taken. It is convenient to take samples with a garden drill, and take samples closer to its axis from the first turn from the tip. A test pinch is placed in a glass jar or glass and technical hydrochloric acid is added; from the admixture of carbonates, the sample begins to foam and bubble, this is the boiling of chernozem. And splash acid, so don't forget your safety precautions and PPE!

If samples from a depth of up to 180-200 cm do not boil or barely boil, your black soil is actually dark gray soil (to the north of black soil) or chestnut soil (to the south). What can be done with them, let's see below, and if you still have black soil, you need to check its pH (acidity) with indicator paper or in the laboratory. There are 3 possible cases: pH = (6.5-7.5), pH<6,5 и pH>7,5.

In the first case, your black soil has not yet degraded and is not very podzolized, just exhausted. It is necessary, firstly, to give him a neutral nitrogen supplement, except for those containing sodium; say, compost is 0.7-0.8 tons per hundred square meters, or half as much as cow manure. This is perhaps the only case when fertilization of black soil is really necessary. It would be even better to sow legumes or on, i.e. in autumn, do not harvest, but plow / bury withered vegetation in the ground. Secondly, to apply gentle agricultural practices, for example. dig not with a shovel, but with a pitchfork. Thirdly, if there is an opportunity and desire, start a vermiculture (see below), regularly give biohumus to the soil and add earthworms in the spring.

With the application of all these measures, regradation may take up to 5-7 years. You can speed it up, especially if, due to climate change, your evaporation has dropped and moisture has increased, you can by completely repartitioning the site. If it is new, then it is better to immediately plant trees not in a separate garden, but evenly over the area with wide row spacings, see the figure in which other crops will be grown. The next year, when the seedlings take root deep enough, it will be possible to buy black soil for adding trunk circles.

In the second case (the earth began to acidify), before applying these measures, it is necessary to carry out its liming. Regradation, as for neutral soil, should begin when the pH rises above 6.5. In the third case, give acidic nitrogen and potassium fertilizers (ammonium sulfate, potassium sulfate). Start regrading when the pH drops to 7.5. In both cases, within 2-3 years, it is possible to achieve an increase in the score from 55-58 to 78-80 or more.

Reclamation

About 20 years ago, the idea of ​​turning your non-chernozem into black soil would have seemed like utter heresy. But let's remember climate change: conditions favorable for the formation of chernozems in the Russian Federation are gradually spreading to the north, there are many underlying carbonate rocks (why is Moscow white-stone?), and modern science offers a lot of means to accelerate soil structuring. Some gardeners and gardeners have already understood this and are successfully using land with a score of more than 80 instead of the previous one of up to 70.

As mentioned above, the chernozem strip is framed from the north and south by gray forest and chestnut soils, respectively. Their structure is shown in Fig. on the right, and there it is clear that there is no fundamental difference between them. As for chestnut soils, they are already very fertile, you just need to help them save water, which is not enough in those parts. The best way to do this is drip irrigation, especially since you can do it yourself. Drip irrigation will not only conserve moisture, but also reduce humus leaching; after 2-4 years, chestnut soil on drip irrigation begins to stain the hand, like real black soil.

With productive serozems, the matter is more complicated. Closer to the south, dark gray forest soils occur (on the left in the next figure), this is the so-called. forest chernozem, potentially highly productive, but poorly structured: it sinters on heating, which requires loosening (dry watering), and its WVV is up to 220-240. Recultivation of dark gray forest soil is possible, firstly, by rational division of the site, as for the regradation of chernozem. Secondly, also to produce its biostructuring using vermiculture (see below).

Note: in terms of humus and nitrogen reserves, dark gray forest soils approach rich chernozems. The composition of forest soils compared with chernozems, see Table. on right.

The gray forest soil (in the center of the figure) does not have a clearly defined horizon A, but in terms of humus and nitrogen it is still suitable for recultivation up to a score of 70-75, which is not bad against its natural 55-58. The TPV of gray forest soils is 180-220, but in conditions of excess moisture over evaporation, this is not a problem. You can help gray forest soil become more nutritious in the same way as forest black soil, but before that you need:

• Plow it into the fall and let it rest under fallow for a year so that the small roots rot.
• Plant legumes and feed with potassium humate NPK with trace elements.
• Apply vermiculture for biostructuring.

And what to do with light gray (on the right in the figure) and soddy-podzolic soils? So far, unfortunately, there is no way to “pull” them to the chernozems. It is possible to conduct a profitable economy on them, but agricultural technology will be different.

Worms to the rescue

Vermiculture means breeding earthworms. This, by the way, is a profitable business in itself: fishermen and pet stores willingly buy worms for animal feed. There are even special breeds of worms for vermiculture: Grindal worm, California worm, Prospector worm, etc. In addition to biomass, vermiculture also provides a highly valuable fertilizer - biohumus, or vermichay, also known as concentrated soil solution (CPR).

For the purposes of soil reclamation/regradation, it is not necessary to purchase the mother material of exotic earthworms. On the contrary, our natives will do better. From late spring to the next spring, they are able to increase the biomass of the population by 300-500 times, then most of the brood is applied to the soil, and the accumulated CPR is used as humates.

Vermiculture is carried out in vermicomposters, a kind of hives for worms. The vermicomposter takes up no more space than a stool, requires almost no maintenance and does not stink. They feed the worms with food waste. About the principles of vermiculture and how to make a vermicomposter with your own hands, see the video:

Note: in all cases of using vermiculture to improve the soil, it is advisable to first cover the near-trunk circles of trees with purchased chernozem and add worms there. In the ecological niches between the roots, the worms will successfully multiply and spread throughout the site during the summer. CRC in this case feed the crops in the aisles.

And what about the environment?

Okay, let's make our garden soil look like black soil. But how will this affect the environment? What happens if everyone does this? First, the chernozem is not Chernobyl, not a coal mine, and not even a quarry. No harm from it, except for benefits, has not been noticed.

The second - in nature, chernozem also occurs in spots. Let's take, for example, the black earth Mecca - the Voronezh region, it was from here that Dokuchaev took the slices that received a gold medal at the World Exhibition in Paris. Here is a field of fat, powerful black soil: humus 10.5%, layer A + B 90 cm. Across the road is an oak forest on gray forest soil. There are green glades in the forest; dig - and there is a typical black soil. The oak brava stretches from the highway for about 3 km, then a country road on the sand and cottages. A plot of 20 acres is divided diagonally in half: leached black soil and sandy loam.

In general, there are no legislative prohibitions on increasing soil fertility with one's own hands on one's own land, and there are no biological ones. So - good luck to high yields of environmentally friendly products!

INTRODUCTION

More than 10% of the world's agricultural land is located in Russia. According to media reports, our country has remained the last large reserve of agricultural land on the planet, at least in the "civilized" world. Therefore, knowledge of our land resources suitable for agriculture has recently become of exceptional importance. According to the founder of Russian soil science V.V. Dokuchaev, “our vegetative-terrestrial soils (represented by chernozem) are not some kind of mechanical, random, lifeless mixtures, but, on the contrary, are independent, definite and subject to known laws, natural historical bodies” (1).

1. CHARACTERISTICS OF CHERNOZEM

Compound

Chernozem provides a rather heterogeneous mass: pieces of quartz, humus flakes, and sometimes fragments of limestone, feldspar and even granite pebbles come across here together.

It is very rich in humus (dark organic matter, one might say, natural manure) and the most important readily soluble plant nutrients, which are: phosphoric acid, nitrogen, alkalis, etc. , and composition) with underlying rocks (subsoil), which themselves (loess) in the vast majority of cases are very rich in soluble nutrients and endowed with excellent physical properties.

Structure

Chernozem is such a plant-terrestrial soil, the average thickness of which is about 60 cm. Under the sod, 5–8 cm thick, there is a dark homogeneous loose mass - humus, consisting of grains or grains, sometimes roundish, but more often representing irregular polyhedra. This horizon in unplowed, virgin areas is overflowing with hundreds of thousands of living and dead underground parts of herbaceous plants. The average thickness of horizon A (the accepted designation according to V.V. Dokuchaev) is 30–45 cm. At the bottom, the soil horizon merges completely imperceptibly with the transitional horizon, which in fact, in all its features (physical and chemical), is a gradual transition from the upper (A) horizon to the lower (C) subsoil. The thickness of horizon B is also 30-45 cm. The subsoil - base (C) in the vast majority of cases consists of loess (light yellow, very loose loam rich in carbonates), but often it is also composed of sandy loam, chalk, limestone, marl, etc. ., and always the subsoil (C) gradually passed into the upper soil horizons (A and B), giving them a strictly defined mineral character. Thus, the chernozem in all natural, undisturbed (in one way or another) sections represents a gradual, closest genetic connection with the subsoil, whatever its composition may be.

Types

There are the following subtypes of chernozem soils:

Podzolized chernozems,

leached chernozems,

Chernozems are typical,

ordinary chernozems,

Southern chernozems.

Properties

1. In connection with its composition, chernozem always has a more or less dark color and is favorable to warmth and moisture. Color is a typical external sign: the color of black soil, whether the latter contains up to 15% humus or no more than 3-4%, always turns out to be more or less dark,

2. The replenishment of chernozem, that is, the ability to become much more ripe (in the agricultural sense), that is, such that the subsurface horizon of which is approximately the same composition in structure as the arable one.

3. Another typical constant feature is the average thickness of the chernozem, which ranges from 60 to 140 cm.

2. AREAS OF DISTRIBUTION

According to V.V. Dokuchaev, chernozem is always and everywhere the result of cumulative activity:

a) bedrocks (subsoil) on which it still lies;

b) the climate that surrounds this soil now and surrounded it in the past (latitude and longitude, the nature of precipitation, temperature, winds);

c) wild vegetation that grew there and still grows to this day in places untouched by culture.

The areas of distribution of fertile plains in the world are: the steppes of Europe and Asia, the savannas of Africa, Australia, the prairies of North and the pampas of South America, Venezuela, Brazil.

On the territory of Russia, chernozems are common in the regions of the Volga region, the Urals, the North Caucasus, the Lower Don and Western Siberia. The heart of the black earth belt is the Voronezh and Saratov regions. The mass of chernozem soils in the world is 48%, in Russia - 8.6%, which is 1.53 million km 2.

3. APPLICATION

Chernozem soils withstand long-term cultivation without any fertilizer and every time, under favorable climatic conditions, give excellent yields of rice, cereals, sunflowers, beets, fodder, fruits, grapes and other industrial and vegetable crops. The natural fertility of chernozem soils makes it possible to fully satisfy the population's need for food products, provides a significant part of the raw materials for light industry, and ensures livestock breeding.

The sector is temperate continental, characterized by alternation of moisture and dryness, as well as the dominance of positive temperatures. Average annual temperature - +3…+7 °C; the annual amount of precipitation is 300-600 mm.

The relief is wavy-flat (periodically cut by depressions, beams, ravines, river terraces).

The vegetation is a perennial herbaceous meadow-steppe and steppe subzone, annually leaving a significant amount of plant residues in the soil. Under appropriate hydrothermal conditions, they decompose with the formation of humus compounds (humification) accumulated in the upper layers of the soil. Together with humus in the soil in the form of complex organo-mineral compounds, plant nutrients such as nitrogen, phosphorus, sulfur, iron, etc. are fixed.

Soil profile structure

• A - humus-accumulative horizon
• B - transition horizon
• C - mother breed

Properties

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

Kinds

Divided into 2 gradations:

According to the thickness of the humus layer (A + AB)

• a) heavy duty (power more than 120 cm.)
• b) powerful (120-80 cm.)
• c) medium power (80-40 cm.)
• d) low power (<40 см.)

According to the content of humus % in Ap

• a) obese (>9%) (black color)
• b) medium humus (9-6%) (black)
• c) low humus (6-4%) (dark gray)
• d) slightly humus (<4 %) (серая)
• e) microhumic (<2 %) (светло-серая)

Subtypes

• podzolized chernozems
• leached chernozems
• typical chernozems
• ordinary chernozems
• southern chernozems

Chernozem zones

Geographically, chernozems occupy significant areas. In Eurasia, the black earth zone covers Hungary, Bulgaria, Austria, the Czech Republic, Slovakia, the Balkan Peninsula, Moldova, Ukraine, Mongolia and China, the central black earth regions of Russia, the Volga region, the North Caucasus, Western Siberia.

Russia occupies the leading place in the world among the countries where black soils are widespread. The areas of Russian chernozems make up 52% ​​of the world's areas. Chernozems of Ukraine occupy an area of ​​27.8 million hectares, which is 8.7% of the world's area.

History of the study of chernozems

Professor of Moscow University M. I. Afonin in 1771 for the first time proposed to collect and study black soil in museums:

I consider it useful to propose that not only various types of soil called chernozem, but also other types of earth, be collected and disposed of in the same way as mineralogists act in the collection and arrangement of Mineral Cabinets. That is, arrange them into their genera and species and store them not only with a note of their properties, names, and that county and village, but also the field itself, from which such land will be taken and how or in what way it is used in arable land.

The monolith of black soil, as a special exhibit, was shown in 1889 at the World Exhibition in Paris.

see also

• Bayrach forests are the most powerful black soil

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Literature

• Glazovskaya M. A. Soils of the world. T. 1-2. - M.: Publishing House of Moscow State University, 1972-73.
• Classification and diagnostics of soils of the USSR. - M.: Kolos, 1977. - 223 p.
• Mineev V. G., Pannikov V. D. Soils, climate, fertilizers and crops. - M.: Agropromizdat, 1987. - 512 p.

Notes

An excerpt characterizing the Chernozems

The officers laughed.
- If only to scare these nuns. Italians, they say, are young. Really, I would give five years of my life!
"They're bored, after all," said the bolder officer, laughing.
Meanwhile, the retinue officer, who was standing in front, pointed out something to the general; the general looked through the telescope.
“Well, it’s true, it’s true,” the general said angrily, lowering the receiver from his eyes and shrugging his shoulders, “it’s true, they’ll start hitting the crossing. And what are they doing there?
On the other side, with a simple eye, the enemy and his battery were visible, from which a milky white smoke appeared. Following the smoke, a long-range shot rang out, and it was clear how our troops hurried at the crossing.
Nesvitsky, panting, got up and, smiling, approached the general.
“Would your Excellency want to have a bite to eat?” - he said.
- It's not good, - said the general, without answering him, - ours hesitated.
“Would you like to go, Your Excellency?” Nesvitsky said.
“Yes, please go,” said the general, repeating what had already been ordered in detail, “and tell the hussars to be the last to cross and light the bridge, as I ordered, and to inspect the combustible materials on the bridge.
“Very well,” answered Nesvitsky.
He called a Cossack with a horse, ordered him to put away his purse and flask, and easily threw his heavy body onto the saddle.
“Really, I’ll stop by the nuns,” he said to the officers, who looked at him with a smile, and drove along the winding path downhill.
- Nut ka, where he will inform, captain, stop it! - said the general, turning to the gunner. - Get rid of boredom.
“Servant to the guns!” the officer commanded.
And a minute later the gunners merrily ran out of the fires and loaded.
- First! - I heard the command.
Boyko bounced 1st number. A gun rang out metallically, deafeningly, and a grenade flew whistling through the heads of all our people under the mountain and, far from reaching the enemy, showed the place of its fall with smoke and burst.
The faces of the soldiers and officers cheered up at this sound; everyone got up and took up observations of the visible, as in the palm of your hand, movements below our troops and in front - the movements of the approaching enemy. The sun at that very moment completely emerged from behind the clouds, and this beautiful sound of a single shot and the brilliance of the bright sun merged into one cheerful and cheerful impression.

Two enemy cannonballs had already flown over the bridge, and there was a crush on the bridge. In the middle of the bridge, dismounted from his horse, pressed with his thick body to the railing, stood Prince Nesvitsky.
He, laughing, looked back at his Cossack, who, with two horses in a lead, was standing a few steps behind him.
As soon as Prince Nesvitsky wanted to move forward, the soldiers and wagons again pressed against him and again pressed him against the railing, and he had no choice but to smile.
- What are you, brother, my! - said the Cossack to the Furshtat soldier with a wagon, who was pushing against the infantry crowded v the very wheels and horses, - what a you! No, to wait: you see, the general must pass.
But the furshtat, ignoring the name of the general, shouted at the soldiers blocking his way: “Hey! compatriots! keep to the left, stop! - But the countrywomen, crowding shoulder to shoulder, clinging with bayonets and without interruption, moved along the bridge in one continuous mass. Looking down over the railing, Prince Nesvitsky saw the fast, noisy, low waves of the Enns, which, merging, rippling and bending near the piles of the bridge, overtook one another. Looking at the bridge, he saw equally monotonous living waves of soldiers, kutas, shakos with covers, knapsacks, bayonets, long guns and from under the shakos faces with wide cheekbones, sunken cheeks and carefree tired expressions, and moving legs along the sticky mud dragged onto the boards of the bridge . Sometimes, between the monotonous waves of soldiers, like a splash of white foam in the waves of Enns, an officer in a raincoat, with his physiognomy different from the soldiers, squeezed between the soldiers; sometimes, like a piece of wood winding along the river, a foot hussar, orderly or inhabitant was carried away across the bridge by waves of infantry; sometimes, like a log floating on a river, surrounded on all sides, a company or officer's cart floated over the bridge, superimposed to the top and covered with skins, a wagon.
“Look, they burst like a dam,” the Cossack said, stopping hopelessly. – How many of you are still there?
- Melion without one! - Winking, a cheerful soldier, passing close in a torn overcoat, said and disappeared; behind him passed another, old soldier.
“When he (he is an enemy) starts frying a taperich across the bridge,” the old soldier said gloomily, turning to his comrade, “you will forget to itch.
And the soldier passed. Behind him, another soldier rode in a wagon.
“Where the devil did you put the tucks in?” - said the batman, running after the wagon and groping in the back.
And this one passed with a wagon. This was followed by cheerful and, apparently, drunken soldiers.
“How can he, dear man, blaze with a butt in his very teeth ...” one soldier in a highly tucked overcoat said joyfully, waving his arm wide.
- That's it, that's sweet ham. replied the other with a laugh.
And they passed, so that Nesvitsky did not know who was hit in the teeth and what the ham referred to.
- Ek is in a hurry that he let in a cold one, and you think they will kill everyone. said the non-commissioned officer angrily and reproachfully.
“As it flies past me, uncle, that core,” said a young soldier with a huge mouth, barely restraining himself from laughter, “I just froze. Really, by God, I was so frightened, trouble! said this soldier, as if boasting that he was frightened. And this one passed. It was followed by a wagon unlike any that had passed before. It was a German fallow steamer, loaded, it seemed, with a whole house; Behind the bowstring, which was carried by a German, a beautiful, motley, with a huge neck, cow was tied. On the feather bed sat a woman with a baby, an old woman and a young, purple-haired, healthy German girl. Apparently, these evicted residents were let through by special permission. The eyes of all the soldiers turned to the women, and while the wagon passed, moving step by step, all the remarks of the soldiers referred only to two women. On all faces there was almost the same smile of obscene thoughts about this woman.
- Look, the sausage is also removed!
“Sell your mother,” another soldier said, striking on the last syllable, addressing the German, who, lowering his eyes, walked angrily and frightened with a long step.
- Ek got away like that! That's the devil!
- If only you could stand by them, Fedotov.
- You see, brother!
- Where are you going? asked an infantry officer who was eating an apple, also half smiling and looking at the beautiful girl.
The German, closing his eyes, showed that he did not understand.
“If you want, take it,” said the officer, giving the girl an apple. The girl smiled and took it. Nesvitsky, like everyone on the bridge, did not take his eyes off the women until they had passed. When they had passed, the same soldiers were walking again, with the same conversations, and, finally, everyone stopped. As is often the case, at the exit of the bridge, the horses in the company's wagon hesitated, and the whole crowd had to wait.
- And what do they become? Order is not! the soldiers said. - Where are you going? Damn! There is no need to wait. Worse than that, he will set fire to the bridge. Look, they’ve locked up the officer, ”the stopped crowds said from different directions, looking at each other, and still huddled forward towards the exit.
Looking under the bridge at the waters of the Enns, Nesvitsky suddenly heard a sound that was still new to him, rapidly approaching ... something large and something splashed into the water.

Let us first dwell on a brief description of the soil formers characteristic of the steppe zone.
We can characterize the climate of the steppe zone, generally speaking, as continental, dry, especially in the eastern part of the described zone. At the same time, the dryness of the climate here is determined not so much by the small amount of precipitation, but by the nature of their precipitation and other meteorological conditions. Indeed, in the steppe zone during the year, on average, precipitation is from 400 to 500 mm, which almost corresponds to the amount of precipitation in some northern regions of Russia. But, firstly, precipitation falls in the steppe zone, usually in the form of showers, which, due to the fine earth content and poor water conductivity of chernozem soils, do not have time to be completely utilized last and largely drain uselessly into low places, ravines, etc. Further, Precipitation these are confined mainly to the summer months, when, due to the high temperature, their evaporation reaches a maximum (their approximate distribution during the year is as follows: about 200 mm in summer, about 100 mm in autumn, about 80 mm in spring and about 70 mm in winter).
The low relative humidity of the air in the steppe zone, which sometimes reaches no more than 45% in the summer months, also contributes to a large evaporation of precipitation. Let us add here the drying effect of the so-called "dry winds" - such common winds for the described zone, the drying effect of a powerfully developed system of ravines and gullies, creating, as it were, natural drainage of the area and increasing the surface of contact of the soil with air, etc.
Thus, the soils of the described type are for most of the year under conditions of such moisture, which explains to us the relatively low leaching of these soils, which can be expressed in the removal from the soil stratum of only easily soluble salts (sodium and calcium) that were present in the original parent rock and formed in the process of weathering of the latter; on the other hand, there is a relatively weak decomposition of the remains (vegetable and animal) accumulated in their surface horizons.
However, it should be noted that by the beginning of the growing season, i.e., by spring, the surface horizons of soils of the type of soil formation under consideration, undoubtedly, are still more or less provided with moisture for the production of a huge amount of plant mass, which is expressed by herbaceous flora with a short vegetation period. period: meltwater and spring precipitation, due to the relatively low temperature at this time of the year and still relatively weak evaporation, still water the soil to a large extent. But, since there are few moisture reserves in the soil (due to the above reasons), by the middle of summer they are already drying up, and the steppe begins to burn out, taking on a dull look. The production of a huge plant mass is also facilitated by the comparative richness of the described soils in nutrient minerals, which we will discuss below. Thus, chernozem soils annually receive a huge amount of material for the construction of humus compounds.
The parent rocks on which chernozem soils are formed are very diverse. In the European part of Russia, the chernozem region is characterized by the extensive development of loess and loess-like rocks that replace it. In addition, chernozems often occur (in the northern part of their distribution) on various moraine sediments (clays, loams), on red-brown clays (in the south), on marine solonetsous variegated clays and on sandy deposits (very, however, rarely) of the Aral-Caspian sea ​​(southeast).
You can often find rocks and more ancient systems as parent parent rocks - Jurassic marl clays (for example, in the southeast of the Gorky region), Jurassic gray clays (for example, in the Oryol region), limestones, sandstones and other rocks of the Upper Cretaceous, Tertiary and Jurassic deposits (for example, in the Saratov region of the Ulyanovsk region, etc.). Finally, chernozem soils are described that form directly on the products of weathering of crystalline rocks (for example, olivine-basalts in the Lori steppe in Transcaucasia, etc.). In Siberia, the parent rocks for chernozem soils are loess-like loams, shale clays, tertiary clays, weathering products of crystalline rocks, etc.
The chernozem type of soil formation is most pronounced precisely on loess and loess-like rocks, i.e., substrates characterized by fine earth, fine porosity and richness in calcium carbonates (CaCO3), as well as all other minerals necessary for higher plants. To a greater or lesser extent, these properties are also inherent in all other parent rocks on which chernozem soils are formed and which we discussed above.
The characteristic features possessed by loess and loess-like rocks impose a very definite imprint on the soils formed on them and predetermine the question that the absorbing complex of these soils (both mineral and organic) will be saturated with calcium (and magnesium) CO with all the numerous resulting hence the consequences (the resistance of the humate and aluminosilicate parts of the soil to the decomposing and dissolving action of soil water, the strength of the structure, etc.).
The acquisition of this basic property by soils of the chernozem type of soil formation is, of course, also favored by those climatic features that we spoke about above (the relatively small amount of water entering the described soils, due to which the hydrogen ion cannot, of course, have a place in the absorbing complex of these soils ).
Relief. Except for the northern subzone of the steppe zone with the so-called northern - degraded and leached - chernozems, which is characterized by an undulating relief (with relatively small plains, slightly sloping spaces), coinciding with the development of glacial deposits, then for the rest of the chernozem zone (middle and southern) the most typical is a flat relief with very soft contours (at present it seems to be dissected by ravines and gullies of the latest formation, especially the middle part of the described zone).
Such a monotonous and flat relief, protecting the parent rock during the processes of soil formation undergoing by it from the phenomena of erosion, washing away and alluvium, contributed in the best possible way to the calm course of the mentioned processes and the formation as a result of the latter of those highly organized natural bodies, which are typical and "fat" chernozems occupying just plain watersheds. Except for steep slopes, gullies and ravines and strongly dissected elevated areas occupied by forest soils, then throughout the rest - often huge - we can observe an extremely uniform soil cover; along the flat watersheds, we see the so-called "mountain" chernozems (typically developed "fat" chernozems), and along the gentle slopes - lighter differences: loamy and sandy loam ("valley" chernozems).
Thus, the mentioned soil former (relief) also contributes to the creation and formation of certain properties and features of the described soil type.
Flora and fauna. At present, it can be considered established that our steppe zone was originally treeless and that it was steppe vegetation (represented by cenoses of grass and shrub-grass steppes), and not forest, that took part in the formation of chernozem soils. The latter, as we will see below, cannot form the chernozem soil type, and if, due to certain conditions, it begins to take possession of the steppe spaces, it inevitably leads to the degeneration (degradation) of these soils, pushing them along the path of podzol formation processes. The forest, as they say, "eats up the black soil." We will return to this issue in more detail below. We consider it necessary to make a reservation that we can talk about the eternal treelessness of our steppes only insofar as we consider this phenomenon from the time of the deposition of those soil-forming rocks (loess, loess-like loams, etc.) on which modern soils began to develop (i.e., soils). since the end of the Ice Age). Until that time, the picture of the distribution of vegetation on the European continent was, as is known, completely different - in connection with a completely different distribution of climatic conditions.
The composition of steppe vegetation, even within the same European part of Russia, is very diverse. In general, two subzones can be outlined here: the subzone of feather grass steppes, which cover the chernozems of the drier southern regions (with tyrsa, fescue, fine-legged, wheatgrass, etc.), and the subzone of meadow steppes, confined to less arid regions (in addition to various cereals, we see here is a rich flora of dicotyledonous plants, let's name some representatives of both: meadow bluegrass, wheatgrass, chapoloch, clover, adonis, sage, astragalus, sainfoin, tumbleweed, and many others).
The steppe vegetation involved in the formation of chernozem soils must be characterized biologically as a set of forms that have a relatively short growing season, enabling them to complete their development cycle by the onset of that dry period that reaches the steppe zone by about mid-July (see above for the description climate of the steppe zone) and more or less freely endure that comparative excess of mineral salts, which we generally observe in soils of the chernozem type.
The richness of humus in chernozem soils, which is so characteristic of them, is partly explained by the enormous amount of organic matter that is annually delivered to these soils precisely by grassy, ​​steppe vegetation; a special role in this regard must be assigned to the underground organs of this vegetation, represented by a whole “lace” of a surprisingly branched and powerfully developed root system of the latter. Forest vegetation, on the other hand, in the form of only falling leaves and a relatively poor herbage, can never provide the soil with such abundant material for the construction of humus substances.
In the nature of the development of the root system of steppe plants, penetrating the soil in all directions and braiding it with its thinnest and numerous branches, we can partly see the reason for that strong granular structure that is so characteristic of virgin representatives of chernozem soils; direct observations show that in this case, indeed, "the soil turns out to be broken up into grains or grains, as if interspersed in loops formed by roots" (Keller).
As for the animal world, being represented in the steppe zone by a diverse fauna of various burrowing and burrowing animals, it also makes a significant contribution to the construction of the soils we describe; the systematic mixing of the material of various soil horizons and soil with each other, which leaves a very definite imprint on certain morphological features of chernozem soils, and the extremely perfect and intimate mixing of organic substances with mineral substances, are due to a large extent to the work of precisely those excavators who huddle in such a large number in soil soils of the chernozem zone.
Having become acquainted in general terms with the nature of those soil-forming agents under the influence of which the soil chernozems develop, we will now proceed to a direct study of these latter.
For chernozem soils, namely for their typical representatives, the following basic and characteristic properties inherent in them can be noted.
1. Rich in humus substances (and in particular the "humate" part of the absorbing complex). The amount of humus in typical ("powerful" and "fat") chernozems sometimes reaches a huge value - 18-20%.
Such a wealth of humic substances is due, on the one hand, to the huge amount of organic material annually delivered to the soil by dying vegetation, in the face of both the ground and, in particular, its underground part, on the other hand, the fact that the processes of decomposition of this organic material proceed quite vigorously. only during the spring months, when the surface horizons of the soil are still sufficiently saturated with melt water, and also during the autumn months, when, due to the relatively weak evaporation of atmospheric precipitation from the soil, the moisture content of this soil is still sufficient to maintain, albeit weak , but still the continuous course of the mentioned processes. During the rest of the year, these processes almost freeze: in the summer months due to the rapid depletion of moisture reserves (for the reasons we have discussed above), in winter - due to low air and soil temperatures.
Thus, for the processes of humification (i.e., the processes of transformation of organic constituent parts of plants into constituent parts of soil humus) in the chernozem zone, there are quite favorable conditions, but there is not enough moisture for further decomposition and mineralization of the resulting humic substances - and just at that time , when, due to very favorable temperature conditions, the latter processes could receive a sharp expression.
Further, the very processes of humification of dying organic residues in chernozem soils reach the stage of mainly humic (black) substances, and only in the spring and autumn periods can they move to the stage of more oxidized and more mobile compounds, which, as we know, are "crepe" and "apocrene" substances. Thus, the main components of humus that accumulate in chernozem soils are those compounds that, as we know, are characterized by extremely low solubility and low mobility (the fact of the low mobility of humus in chernozem soils has now been proven by direct experimental data). And in this circumstance, we cannot fail to see a new explanation for the fact that chernozem soils are highly enriched in humus substances.
Finally, if we take the modern point of view and accept that humus substances (or at least a certain part of them) can be in a colloidal state (see above), then bearing in mind the abundance of typical representatives of chernozem soils in such strong coagulants of colloidal particles as are calcium salts, we must assume that the humic substances of the soils under consideration will be in a firmly coagulated state, protecting them from the spraying, dissolving and decomposing action of water. From this it becomes clear to us why the humate part of the absorbing complex in chernozem soils reaches such an enormous value.
In connection with the richness of chernozem soils in humus substances, there is also a very high comparative content of nitrogen in them, the amount of which in "fat", for example, chernozems can reach 0.4-0.5%.
The richness of chernozem soils in phosphorus (0.2-0.3%) must also be connected with the high content of humus in them.
2. Rich in minerals (in particular, the "zeolite" part of the absorbing complex). This characteristic property of typical representatives of chernozem soils is a consequence, on the one hand, of the general richness in mineral compounds of those parent soil-forming rocks (loess and loess-like rocks), on which the described soils get their greatest development and best expression, on the other hand, their relatively low leaching as the result of a certain combination of climatic conditions already known to us in the chernozem zone; finally, the presence in soils of the chernozem type of a large amount of such an energetic coagulator as Ca-ion explains to us the fact why, in particular, the "zeolite" part of the soils described (the aluminosilicate part of the absorbing complex), acquiring special strength and resistance against spraying and the dissolving action of water can reach such a large value (often above 30% of the weight of dry soil).
This "zeolite" part of chernozem soils is very rich in bases: it can be considered that the sum of all bases in it reaches on average up to 50% (the remaining 50% are SiOj).
3. The saturation of their absorbing complex with bases, and the "saturating" ion is exclusively calcium (and magnesium). The climatic features of the steppe region are combined, as we already know, in such a way that only such readily soluble salts as sodium and potassium salts can be removed from the soil stratum in the process of soil formation in significant quantities. Ground waters lie in the described area (due to the same conditions) so deep that the possibility of a reverse rise of these salts into the upper soil horizons is excluded.
On the other hand, in the area described there are all favorable conditions for the preservation at one or another depth in the soil stratum in a large amount of such relatively sparingly soluble compounds, such as alkaline earth metal carbonates.
Thus, taking into account the relatively negligible concentration of alkaline cations in the soil solution of chernozem soils, on the other hand, recalling that calcium generally has a much higher absorption energy (or displacement energy) compared to sodium and potassium (and also magnesium), and magnesium, in turn, has a higher absorption energy (or displacement energy) compared to both of the above-mentioned unambiguous ions, it is not difficult to conclude that the absorbing complex of the soils we describe should contain calcium (primarily) and partly magnesium among the absorbed cations. There is no need to even talk about the hydrogen ion: it cannot compete with alkaline earth cations in any way for a place in the absorbing complex of chernozem soils, since the latter are formed and develop under conditions of insufficient moisture supply to them.
The following table illustrates this situation quite clearly (E.N. Ivanova according to K. Gedroits).

The saturation of the absorbing complex of chernozem soils with calcium (and magnesium), which determines its special strength and resistance to the destructive action of soil water, explains to us, on the one hand, the fact that we noted above is very rich in the described soils in the "zeolite" and "humate" parts (the total value absorbing complex in chernozem soils can reach 50% or more), on the other hand, it causes the presence in typical (“fat” clayey) chernozems of the granular - very strong - structure so characteristic of the latter (due to the sharp coagulating ability inherent in the calcium cation). Such structure, creating a favorable air regime in chernozem soils, provides them with the correct course of aerobic biochemical processes and thereby excludes the possibility of the formation of any incompletely oxidized or ferrous compounds in them.
The above-noted richness of the absorbing complex of chernozem soils explains to us the very high absorbing capacity, which distinguishes these soils so much.
In conclusion, in order to complete the description of the characteristic properties and features of typical chernozems, let us recall the main difference that exists between soils with saturated and unsaturated bases. As is known, the latter contain a hydrogen ion in their colloidal (aluminosilicate and humate) part in the absorbed state. Although this absorbing complex is insoluble in water, nevertheless this hydrogen ion is capable of vigorous exchange reactions on the surface of the elements of this absorbing complex with any cations of those salts that are in the soil solution. As a result of such a reaction, the acid of those anions with which such exchange decomposition took place begins to accumulate in the soil solution. Thus, soils unsaturated with bases (for example, podzolic ones) can always maintain the presence of strong acids in soil solutions - in view of the appearance in the latter acids of anions of those salts that are formed in these soils during their soil formation.
As for soils saturated with bases, to which, as we saw above, chernozems belong, when the elements of their absorbing complex meet with neutral solutions of various salts, bases from the latter are also, of course, absorbed, but with a return to this salt solution the same amount (in molecular terms) of other bases (in this case, calcium and magnesium), as a result of which the soil solution does not change its reaction; changing only its composition.
From this we conclude that the process of chernozem formation usually proceeds in a neutral or even slightly alkaline medium and that, due to the above reasons, the possibility of the formation of free acids in soil solutions of the described soils is excluded (which circumstance, together with the enrichment of chernozem soils with organic substances, creates a very favorable environment for biological processes). Only in certain periods of the life of these soils, due to the vigorous processes of decomposition of organic matter in them (in spring and autumn), can we sporadically state a weakly acidic reaction due to the accumulation of carbon dioxide and bicarbonate carbonates.
The neutral (or weakly alkaline) environment in which the soil-forming process of chernozem soils takes place and the low supply of moisture to them makes it even more understandable for us the fact that we have already noted above that the described soils are relatively little affected by leaching processes: only easily soluble salts are washed out of the soil stratum in typical chernozems. (potassium and sodium); as for the more sparingly soluble calcium and magnesium carbonates, they are not deeply washed out, and their abundant accumulations are usually ascertained even in relatively shallow horizons; finally, for washing out oxides of silicon, aluminum and iron, there are no suitable conditions at all: in the form of true solutions, they cannot move deeper - due to the absence of a favorable reaction of soil solutions, in the form of pseudo-solutions - due to the presence of such a strong coagulant, which is calcium.
The above considerations, in turn, make clear to us the facts of a relatively uniform and homogeneous distribution of all elements over the various horizons of the described soils: the upper horizons, in comparison with the deeper ones, are enriched only in humus substances, and the deep-lying horizons seem to be more enriched in lime and magnesia; the rest of the soil remains almost unaffected by leaching processes and, therefore, seems to be rather homogeneous throughout the entire thickness, which is not difficult to verify by comparing the figures for layer-by-layer analyzes (see below).
The chemical composition of typical chernozems ("fat", "powerful") can be characterized on average by the following numbers of their surface horizons:

Water-soluble compounds typical representatives of chernozem soils contain about 0.1%; Approximately half of this amount is mineral and half is organic.
Of the minerals that pass into the water extract, calcium is in the first place.
As an illustration of the layer-by-layer distribution of individual components in chernozem soils, we present (in an abbreviated form) an analysis of the Saratov (K. Schmidt) and Tobolsk (K. Glinka) chernozems.


The uniformity and homogeneity of the distribution over the various horizons of the described soils of individual components (of which we spoke above) emerge even more clearly if we list the figures given for the anhydrous, carbonate-free and humus-free mineral mass.
For the Tobolsk chernozem, the corresponding quantities (in%) will then be as follows:

Some of the chemical properties and features that are characteristic of typical chernozems and which we have discussed above find a fairly clear expression in a number of peculiar morphological features of these soils.
Morphology of typical chernozems. Horizon A (humus-eluvial) - black, especially when wet. Its power is very large, measured 60 cm and above. The structure is granular, very strong; structural aggregates - rounded or ribbed, 2-3 mm in diameter.
In virgin (virgin) representatives of the described soils, one can observe on the very surface a “steppe felt” 1-3 cm thick, consisting of a semi-decomposed intertwined mass of the remains of roots and stems with an admixture of clay powder particles.
Horizon B (eluvial) is hardly distinguishable from horizon A. Dark, almost black in color. The thickness is 50-70 cm. The structure is somewhat coarser: in the upper subhorizons of the described horizon it is granular-nutty, in the lower - lumpy. These last sub-horizons show already distinct effervescence with hydrochloric acid (presence of exudates of carbonic lime).
Thus, the entire humus horizon of the described representatives of chernozem soils (A + B) reaches a huge thickness, sometimes measured 1-1.5 m. Its characteristic feature is a very gradual (not abrupt) decrease in the amount of humus downwards.
Horizon C (illuvial). Structurality, one might say, is absent; fine porous structure; power measured 40-60 cm; pale gray color. Abundant excretion of calcium carbonates; first in the form of false mushrooms, deeper - in the form of various shapes and sizes of concretions (white-eyed, cranes, etc.). Violent effervescence with hydrochloric acid.
Horizon D (parent rock) - usually loess and loess-like rocks, porous structure, fawn color; vertically fissured.
The abundant fauna of chernozem soils, represented by numerous representatives of burrowing and digging animals, leaves certain traces of their life activity on the soil section of the described soils. Numerous wormholes furrowing the soil profile in all directions, molehills: pale yellow in horizons A and B (as a result of filling them with underlying loess-like rock) and dark in horizon C (as a result of filling them with soil from overlying horizons), etc. - all these neoplasms are rather common companions of typical representatives of chernozem soils.
To complete the consideration of the main morphological features of these soils, we note that sometimes (in loess areas) at a depth of 2-3 m one can observe very original formations in the form of the so-called "second humus horizon", which is an indistinctly formed accumulation of dark humus substances.
In most cases, this phenomenon is not associated with the soil-forming process of modern chernozem soils and is a remnant of buried soils (for example, “former” chernozems buried by layers of loess, on which the soil cover that is modern to us was later formed). Ho, of course, it cannot be denied that in some cases this phenomenon is of purely illuvial origin. We already know that in some periods of the life of chernozem soils (spring and autumn), the processes of decomposition of organic substances can proceed quite vigorously, with the formation, perhaps, of such easily mobile humus components as "crepe" and "apocrene" compounds. Washing out to a certain depth and getting into conditions of insufficient aeration, these compounds will be restored and turn into less mobile dark forms of "humic" substances.
In cases where we observe “the second humus horizon is not too deep, such an explanation of the genesis of the latter is quite appropriate.
Above, we have given a description of the characteristic features of that variety of chernozem soils, which is called "typical" chernozem. The named difference sometimes receives the name of "fat" or "powerful" chernozem.
However, the vast steppe zone is not in all its parts a homogeneous region in terms of climate. In connection with a decrease in precipitation and an increase in temperature, this zone, as we saw above, can now be subdivided into a number of subzones, changing from northwest to southeast. Each subzone corresponds to its own special difference in chernozem, bearing traces of the climatic features of this subzone. In this regard, all the morphological and physicochemical features described above, which are characteristic of typical chernozems, undergo in nature the most diverse variations and deviations from the general scheme in one direction or another. In view of the fact that the transition of some varieties to others is extremely gradual and often even imperceptible, there is no need and opportunity to dwell on a detailed description of the properties and features of all chernozem varieties observed in nature. Therefore, in the future we will only note the main features characteristic of each of them.
Let us preliminarily point out that chernozem soils can now be subdivided into the following differences: 1) northern (or degraded or podzolized) chernozem, 2) leached chernozem, 3) typical chernozem (“powerful”, “fat”), 4) ordinary chernozem, 5) southern chernozem and 6) Azov chernozem.
We will not talk about degraded chernozem now, because it carries all the typical signs of another type of soil formation (namely, podzolic), so we will postpone its description until the time when we will talk about the degradation of chernozem in general.
The leached chernozem is characterized by a significantly lower amount of humus (4-6%) compared to rich chernozems and a lower capacity of the humus horizon - due to the relatively small amount of dying vegetation and a more vigorous rate of its decomposition. The solubility of humus is somewhat higher (1/200-1/250 of its total content) - as a result of more vigorous decomposition of organic residues (due to a less arid climate, with the possible, therefore, partial formation of more mobile components of humus such as "crepe" and " apocrenic acids).
The described difference of chernozem soils seems to be more depleted in calcium carbonates, both due to the greater poverty of this compound in the parent underlying rocks (which are often various moraine sediments - clays and loams), and due to the greater amount of atmospheric precipitation entering these soils. In view of this, the effervescence horizon in the described difference of chernozem soils is much deeper than that of their typical representatives.
The comparative depletion in calcium is the reason for the comparatively lower strength of their absorbing complex; this circumstance, in turn, determines the fact of the relative depletion of their "zeolite" (and, as we indicated above, "humate") part.
The depletion of leached chernozems in such an energetic coagulator as the calcium ion explains to us the interesting fact that in some of the “most leached” representatives we can ascertain hints of the phenomena of the movement of sesquioxides (Al2O3 + Fe2O3) from the upper horizons to the lower ones, i.e. to phenomena that are so characteristic of degraded chernozems (and even more so of podzolic soils, see below), but never observed in typical ("powerful") chernozems.
The presence of a brownish illuvial horizon in some representatives of leached chernozems, as established by a number of researchers, must apparently be connected precisely with the processes just mentioned.
As for the ordinary chernozem, we do not dwell on its characteristics: representing the transition from the typical (“fat”) chernozems we have considered above to the southern ones (see below), it carries all the signs of intermediate formations.
The southern chernozem is characterized, in comparison with the ordinary (and even more so with powerful chernozem), by a significantly lower humus content (4-6%) due to the greater aridity of the climate and some alkalinity of this variety, which phenomena cause a relatively small increase in plant organic mass.
The mentioned solonetzicity (of deep horizons) is the result of a relatively small amount of moisture entering it (strong evaporation, etc.), as well as the nature of those parent rocks on which it usually forms (red-brown clays, marine solonetzic variegated clays, etc.). ).
Hence, we understand the genesis of the gypsum horizon, which is so often present in the section of southern chernozems. Being soluble in water, gypsum (CaSO4.2.H2O) does not find favorable conditions for its isolation and accumulation in all the above varieties of chernozems, undergoing processes of removal from the soil layer almost completely. In this case, due to lack of moisture, it concentrates at a certain depth (usually deeper than the white-eye horizon) and stands out in the form of various shapes and sizes of aggregates consisting of whitish-yellow crystals.
The gypsum horizon is thus a fairly characteristic new formation for southern varieties of chernozem.
There are fewer traces of excavation activity (molehills, wormholes, etc.) than in a typical chernozem, in view of the relatively poorer fauna.
In the regime of the absorbing complex of the described difference of chernozem soils, sodium begins to play a certain role (in any case, still very insignificant - and then only in some individual periods of the life of these soils) due to the low leaching of these soils in general and the alkalinity of the underlying parent rocks in particular, which circumstance explains to us some specific features of these soils, which distinguish them from the previously considered varieties and bring them closer to soils of the desert-steppe type of soil formation (chestnut and brown), for example, the emerging division of horizon A into two subhorizons, of which the deeper one seems to be somewhat darker and somewhat more compacted, the existence of the same compacted horizon under the humus layer, etc.
In view of the fact that southern chernozems very gradually and often imperceptibly pass into chestnut soils, in which the above-mentioned specific features are revealed much more clearly, we will say a little more about these features below when we talk about chestnut soils.
The Azov (or Ciscaucasian) chernozem, described by L. Prasolov, is a peculiar difference of chernozem soils, in the genesis of which the water-thermal conditions created by the proximity of the Sea of ​​\u200b\u200bAzov played an important role. From the morphological side, these chernozems are described in sufficient detail (the enormous thickness of the humus horizon, measured almost 1.5 m; its not too dark color, indicating a relatively small amount of humus substances in it; nutty-lumpy structure; the presence of needle-like crystals already in the surface soil horizons calcium carbonates; poor development of the white-eye horizon, etc.). The details of the soil-forming process of the described variety of chernozem soils seem, however, unclear.
Currently, another variety of chernozem soils is highlighted - "mountain chernozems", common in some intramountain valleys of Dagestan and Transcaucasia, in Armenia, in the foothills of Altai, etc.
As for the mechanical composition of chernozem soils, in this respect we observe a very wide variety among them: starting from heavy clay soils and ending with sandy and even skeletal ones, we can find in nature varieties of chernozem soils that differ greatly in mechanical composition. Loamy varieties, however, are undoubtedly predominant (within the Russian steppes) due to the predominant type of parent rocks in the steppe zone (loess, loess-like loams), which are distinguished by their fine earth content.