This section is devoted to the description of several soil combinations, giving an idea of ​​the classes and main subclasses of combinations. The huge variety of existing subclass combinations made it necessary to select only the most common ones for this review. It should be emphasized that not all of the descriptions are sufficiently complete, due to the nature of the source materials.

1) a complex of solonchak meadow-steppe solonetzes, steppe-stepping meadow-steppe solonetzes, light chestnut meadow and meadow-chestnut soils.

This complex, which occupies vast territories of the Caspian lowland, has been studied in detail (Bolshakov, 1937; Glazovskaya, 1939; Rode, 1958; Rode and Polsky, 1961, etc.). It is formed by soils with meadow-steppe water regime, significantly different in the degree of surface moisture. It occupies vast spaces of the semi-desert undrained plain of the Caspian lowland, where soil formation occurs on silty heavy loams with shallow (5-7 m) groundwater. The plain, in the complete absence of erosional relief forms, is characterized by an abundance of closed depressions-depressions with a depth of 2-5 to 30-50 cm, formed as a result of subsidence phenomena. The main surface between these depressions, from which snow is blown into depressions in winter and meltwater flows in spring, serves as a drainage basin. The highest elements of the microrelief are the butanes (emissions) of ground squirrels, rising 20-50 cm above the main surface and receiving the least amount of moisture.

Depressions occupy 20-25% of the space, the soils developing in them receive additional surface moisture, settle and become more humus, since much richer vegetation grows on them. These soils are classified as meadow-chestnut to varying degrees humus content and desalinity; A. A. Rode and M. N. Polsky (1961) distinguish them depending on humus content and salt profile under the names of chernozem-like dark-colored soils, dark and light chestnut soils. On elevated relief elements, where soils are very weakly moistened by surface waters, and film moisture currents rising from saline groundwater populate the soil profile, meadow-steppe solonchak solonetzes are formed under poor black wormwood and solyanka vegetation. At transitional positions—slopes of the microrelief—meadow light chestnut soils are formed. The soil cover is further complicated by patches of saline soil microhillocks (discharges of diggers) and patches of steppe-forming solonetzes in subsidences that arise in the loosened mass of solonetzes dug up by diggers.

As a result of this entire sum of processes, a very complex II contrasting soil complex of background structure arises. The background soil of this complex is meadow-steppe solonchak solonetzes, occupying 40-50% of the area. This background ESA is classified as sporadic-spotted, since spots of dug-up solonetzes and solonchaks, which represent limiting structural elements (LSE), are scattered on its surface.

Various meadow-chestnut soils form rounded closed ESAs with an area of ​​several square meters up to two hundred to three hundred square meters. EPAs with a size of 30-60 square meters predominate. m. Small rounded ESAs are formed by steppe solonetzes. Meadow light chestnut soils in transitional positions form predominantly perforated, often ring-shaped ESAs having small areas (mainly 50-100 sq. m). A profile through this complex reveals very significant differences in soil properties, indicating a high contrast of the soil cover represented by the complex under consideration. Thus, drainage, the presence of subsidence microrelief, shallow occurrence of saline groundwater, redistribution of moisture by microrelief, as well as redistribution of snow, which determine the differentiation of vegetation, and the digging activity of animals create a very complex and very contrasting soil cover in a semi-desert climate.

The complex belongs to the subclass of solonetzes, the family of meadow-steppe closed-monochronous, the type of meadow-chestnut-solonetzes, the subtype with a predominance of solonetzes, the series of background round-areal, the subgroup of moderately dissected, the discrete clan.

The described complex forms a complex combination with the dark-colored, highly leached (meadow-chestnut) soils of the depressions - large closed depressions into which snow is blown in winter, and in the spring water flows from the surrounding interdepression complex plain. The depth of the depressions ranges from 40-50 to 100-150 cm, and the area from 2-3 to hundreds of hectares.

Spots are very widespread, but their low contrast, and therefore their low significance in the practical use of soils, makes them not such an attractive object; research as complexes, and therefore they have been studied very poorly.

2) patchiness of typical chernozems, in some places interspersed with leached chernozems.

This spotting was described (Daineko, 1968) in the virgin Streletskaya steppe of the Central Black Earth Nature Reserve near Kursk in the southwestern part of the Central Russian Upland. Here, on the near-watershed and ravine slopes, the hollow microrelief is clearly expressed; In the spaces between the hollows there are often tubercles, which are the result of the activity of excavators. Increased moisture in the hollows causes the formation of leached, thick, thick chernozems in them. The main inter-hollow area is occupied by typical thick thick chernozems, among which are scattered patches of thick thick marmot chernozems. Thus, the spotting in question is formed by two ESAs - a homogeneous EPL of leached chernozems and a sporadic spotted ESA of marmot chernozems typical with PSE. Differences in the structure of the soils that form this patchiness lie mainly in the depth of carbonates, which is characterized through the depth of boiling. Thus, PC components are very similar in their properties. very low contrast. At the same time, they are genetically closely interrelated, as was shown in the works of A.F. Bolshakov (1961) and E.A. Afanasyeva (1966). The foregoing gives us reason to classify the combination in question as spotting.

Within the reserve, this spotting was studied in great detail; it was found that on the watershed slopes the ratio of its components is approximately as follows: Cht-50-60%; Chs- 20-25% II Chv-20-25%; on the ravine slopes the amount of marmot chernozems noticeably decreases: Chv - 45-50%; Thurs-40-45% and Chs-10-15%. Thus, these spots differ at the subtype level, belonging to the same class, subclass (leaching), family (superficial monochroines) and type (chernozem). The subtype was discussed above; the series is linear-areal, the subgroup is highly dissected, the clan is continuum-discrete.

The described spotting is part of a combination that, in addition to this spotting, also includes complexes of chernozems and meadow-chernozem soils of watersheds and washed-away soils of ravine slopes and bottoms.

3) spotting of typical and leached chernozems.

The spotting in question was studied in detail in the Cossack forest of the Central Black Earth Nature Reserve, 25 km south of Kursk, in the southwestern part of the Central Russian Upland. The studied area is located on a drive-separated slope with a slope of 2-2.5°. The microrelief is represented by drainage depressions having a depth of 15-25 cm and a width from 0.6-1 m to 3-4 m. The soil cover of the area is formed by the patchiness of typical rich thick chernozems and leached thick thick chernozems in its spatial pattern, similar to that just described spotting. Their difference lies in the absence of dug-up chernozems in the patchiness of the Cossack steppe, since in the forest there are no diggers who dig up the soil as deeply and intensively as steppe diggers. Thus, this spotting is formed by homogeneous EPAs. It, like the previous spotting, is part of a complex combination of the first level of complexity, which is very characteristic of the soil cover of the forest-steppe. Spotting belongs to the subclass of leaching, the family of surface-open monochronic, the type of chernozem, the series of linear-areal, the subgroup of highly dissected, the clan of continuum-discrete.

The task of soil classification is to unite soils into taxonomic groups based on structure, composition, properties, origin and fertility. The classification problem in soil science is one of the most difficult, and this is explained primarily by the complexity of the soil as a special body of nature, developing as a result of the simultaneous, cumulative action of all soil formation factors (climate, rock, vegetation and fauna, relief conditions, age), t i.e. as a result of close interaction with the environment.

The basis of the scientific classification of soils is the point of view of soil as an independent special body of nature, the same as minerals, plants and animals. According to this point of view, the classification of soils should be based not only on their characteristics and properties, but also on the characteristics of their genesis, i.e., origin. The first such genetic classification of soils was developed by V.V. Dokuchaev.

This genetic approach is also characteristic of the currently accepted classification of soils. Soviet Union(1977).

The basic unit of soil classification is the soil type. The concept of “soil type” has the same important in soil science, as a species in biological science. Soil type refers to soils formed under the same conditions and having similar structure and properties.

One type of soil includes soils:

1) with similar processes of transformation and migration of substances;

2) with a similar nature of the water-thermal regime;

3) with the same type of soil profile structure across genetic horizons;

4) with a similar level of natural fertility;

5) with an ecologically similar type of vegetation.

Such types of soils as podzolic, chernozems, red soils, solonetzes, solonchaks, etc. are widely known.

Each soil type is successively subdivided into subtypes, genera, species, varieties and categories.

Soil subtypes are groups of soils that differ from each other in the manifestation of the main and accompanying processes of soil formation and are transitional stages between types. For example, when a soddy process develops in the soil along with the podzolic process, a subtype of soddy-podzolic soil is formed. When the podzolic process is combined with the gley process, a subtype of gley-podzolic soil is formed in the upper part of the soil profile.

Subtype features of soils are reflected in the special features of their soil profile. When identifying soil subtypes, processes and characteristics determined by both latitudinal and facial features are taken into account. natural conditions. Among the latter, thermal conditions and the degree of continental climate play a primary role.

Within the subtypes, genera and types of soils are distinguished. Soil genera are distinguished within the subtype according to the characteristics of soil formation, associated primarily with the properties of parent rocks, as well as properties determined by the chemistry of groundwater, or with properties and characteristics acquired in past phases of soil formation (the so-called relict characteristics).

Soil genera are distinguished in each soil type and subtype. Here are the most common ones:

1) ordinary genus, i.e., corresponding in nature to the soil subtype; when defining soils, the name of the genus “common” is omitted;

2) solonetzic (soil characteristics are determined by the chemistry of groundwater);

3) residual solonetzic (soil characteristics are determined by the salinity of the rocks, which is gradually being removed);

4) saline;

5) residual carbonate;

6) soils on quartz-sand rocks;

7) contact-gley soils (formed on two-membered rocks, when sandy loam or sandy strata are underlain by loamy or clayey deposits; at the contact of sediment change, a lightened strip is formed, formed due to periodic waterlogging);

8) residual arid.

Soil types are distinguished within the genus according to the degree of expression of the main soil-forming process characteristic of a particular soil type.

To name species, genetic terms are used that indicate the degree of development of this process. Thus, for podzolic soils - the degree of podzolicity and the depth of podzolization; for chernozems - thickness of the humus horizon, humus content, degree of leaching; for solonchaks - the nature of the distribution of salts along the profile, the morphology of the surface horizon (plump, upturned, faded).

Within species, soil varieties are determined. These are soils of the same type, but with different mechanical compositions (for example, sandy, sandy loam, loamy, clayey). The soils are of the same type and one mechanical composition, but developed on source rocks of different origins and different petrographic compositions, are distinguished as soil categories.

Here is an example of determining soil before discharge:

type - black soil,

subtype - ordinary chernozem,

genus - ordinary solonetzic chernozem,

species - ordinary solonetzous chernozem with low humus content,

variety - ordinary solonetzic, low-humus, silty-loamy chernozem,

category - ordinary solonetzic, low-humus, silty-loamy chernozem on loess-like loams.

Land has always occupied a dominant place among the national wealth of any state. The table below shows data on the planet’s soil resources, distribution various types soil Data on their economic development is also provided here. Depending on the characteristics of the structure, mechanical and chemical composition, all types of soils are divided into subtypes, genera, types and varieties.

Table 1

Prevalence of the world's main soil types and the degree of their development

Geographic zones and soil types	Total area	Percentage of completion
million km2	%
Tropical zone
Rain forest soils – red and yellow ferrallitic soils	25,9	19,5	7,4
Soils of seasonally wet landscapes – red savannah, black drainage	17,6	13,2	12,6
Soils of semi-deserts and deserts	12,8	9,6	0,8
Subtropical zone
Soils of constantly wet forests - red soils, yellow soils	6,6	4,9	19,7
Soils of seasonally wet landscapes are brown, etc.	8,6	6,5	25,6
Soils of semi-deserts and deserts	10,6	7,9	7,6
Subboreal belt
Soils of deciduous forests and prairies - brown forest, etc.	6,1	4,6	33,4
Soils of steppe landscapes – chernozems, chestnut	7,9	5,9	31,6
Soils of semi-deserts and deserts	7,9	5,9	1,3
Boreal belt
Soils of coniferous and mixed forests – podzolic, soddy-podzolic	15,5	11,6	8,4
Soils of permafrost-taiga landscapes	8,2	6,1	-
Polar belt
Soils of tundra and arctic landscapes	5,7	4,3	-

Now on Earth, the leading position in terms of prevalence is occupied by four typological groups of soils:

1) soils of the humid tropics and subtropics, mainly red soils and yellow soils, which are characterized by richness mineral composition and high mobility of organic matter (more than 32 million km2);

2) fertile soils of savannas and degrees - chernozems, chestnut and brown soils with a thick humus layer (more than 32 million km2);

3) poor and extremely unstable soils of deserts and semi-deserts, belonging to different climatic zones(more than 30 million km2);

4) relatively poor soils of temperate forests - podzolic, brown and gray forest soils(more than 20 million km2).

Soils are classified by type. The first scientist to classify soils was Dokuchaev. On the territory of the Russian Federation there are following types soils: podzolic soils, tundra gley soils, arctic soils, permafrost-taiga, gray and brown forest soils and chestnut soils.

Tundra gley soils are found on plains. They are formed without much influence from vegetation. These soils are found in areas where there is permafrost (in the Northern Hemisphere). Often, gley soils are places where deer live and feed in summer and winter. An example of tundra soils in Russia is Chukotka, and in the world it is Alaska in the USA. In areas with such soils, people engage in farming. Potatoes, vegetables and various herbs grow on such land. To improve the fertility of tundra gley soils, the following types of work are used in agriculture: drainage of the most moisture-saturated lands and irrigation of arid areas. Methods for improving the fertility of these soils also include adding organic and mineral fertilizers.

Arctic soils are produced by thawing permafrost. This soil is quite thin. The maximum layer of humus (fertile layer) is 1-2 cm. This type of soil has a low acidic environment. This soil cannot be restored due to the harsh climate. These soils are common in Russia only in the Arctic (on a number of islands in the Arctic Ocean). Due to the harsh climate and small layer of humus, nothing grows on such soils.

Podzolic soils are common in forests. There is only 1-4% humus in the soil. Podzolic soils are obtained through the process of podzol formation. A reaction occurs with the acid. That is why this type of soil is also called acidic. Dokuchaev was the first to describe podzolic soils. In Russia, podzolic soils are common in Siberia and the Far East. Around the world, podzolic soils are found in Asia, Africa, Europe, the USA and Canada. Such soils must be properly cultivated in agriculture. They need to be fertilized, organic and mineral fertilizers. Such soils are more likely to be useful in logging than in agriculture. After all, trees grow better on them than crops. Soddy-podzolic soils are a subtype of podzolic soils. Their composition is largely similar to podzolic soils. Characteristic feature These soils are that they can be washed out more slowly by water, unlike podzolic soils. Soddy-podzolic soils are found mainly in the taiga (the territory of Siberia). This soil contains up to 10% fertile layer on the surface, and at depth the layer sharply decreases to 0.5%.

Permafrost-taiga soils were formed in forests under permafrost conditions. They are found only in continental climates. The greatest depths of these soils do not exceed 1 meter. This is caused by the proximity to the surface of permafrost. The humus content is only 3-10%. As a subspecies, there are mountainous permafrost-taiga soils. They form in the taiga on rocks that are covered with ice only in winter. These soils are found in Eastern Siberia. They are found in the Far East. More often, mountain permafrost-taiga soils are found next to small bodies of water. Outside Russia, such soils exist in Canada and Alaska.

Gray forest soils are formed in forest areas. A prerequisite for the formation of such soils is the presence of a continental climate. Deciduous forest and herbaceous vegetation. The places of formation contain an element necessary for such soil - calcium. Thanks to this element, water does not penetrate deep into the soil and does not erode them. These soils gray. The humus content in gray forest soils is 2-8 percent, that is, the soil fertility is average. Gray forest soils are divided into gray, light gray, and dark gray. These soils predominate in Russia in the territory from Transbaikalia to the Carpathian Mountains. Fruit and grain crops are grown on the soils.

Brown forest soils are common in forests: mixed, coniferous and broad-leaved. These soils are found only in warm temperate climates. The soil color is brown. Typically brown soils look like this: on the surface of the ground there is a layer of fallen leaves, about 5 cm high. Next comes the fertile layer, which is 20 and sometimes 30 cm. Even lower is a layer of clay of 15-40 cm. There are several subtypes of brown soils. Subtypes vary depending on temperatures. There are: typical, podzolized, gley (superficial gley and pseudopodzolic). On the territory of the Russian Federation, soils are distributed in the Far East and in the foothills of the Caucasus. Low-maintenance crops such as tea, grapes and tobacco are grown on these soils. Forests grow well on such soils.

Chestnut soils are common in steppes and semi-deserts. The fertile layer of such soils is 1.5-4.5%. Which indicates average soil fertility. This soil has chestnut, light chestnut and dark chestnut colors. Accordingly, there are three subtypes of chestnut soil, differing in color. On light chestnut soils, farming is possible only with abundant watering. The main purpose of this land is pasture. The following crops grow well on dark chestnut soils without watering: wheat, barley, oats, sunflower, millet. There are slight differences in the chemical composition of chestnut soil. It is divided into clayey, sandy, sandy loam, light loamy, medium loamy and heavy loamy. Each of them has a slightly different chemical composition. Chemical composition chestnut soil is varied. The soil contains magnesium, calcium, and water-soluble salts. Chestnut soil tends to recover quickly. Its thickness is maintained by annually falling grass and leaves of trees rare in the steppe. You can get good harvests from it, provided there is a lot of moisture. After all, steppes are usually dry. Chestnut soils in Russia are common in the Caucasus, the Volga region and Central Siberia.

There are many types of soils on the territory of the Russian Federation. They all differ in chemical and mechanical composition. At the moment, agriculture is on the verge of crisis. Russian soils must be valued like the land on which we live. Care for soils: fertilize them and prevent erosion (destruction).

Conclusion

Soil is a colossal natural resource that provides humans with food, animals with feed, and industry with raw materials. It was created over centuries and millennia. To use soil correctly, you need to know how it was formed, its structure, composition and properties.

The soil has a special property - fertility, it serves as the basis agriculture all countries. Soil at correct operation not only does it not lose its properties, but also improves them and becomes more fertile. However, the value of soil is determined not only by its economic significance for agriculture, forestry and other sectors of the national economy; it is also determined by the irreplaceable ecological role of soil as the most important component of all terrestrial biocenoses and the Earth’s biosphere as a whole. Through the soil cover of the Earth there are numerous ecological connections of all organisms living on earth (including humans) with the lithosphere, hydrosphere and atmosphere.

From all of the above, it is clear how great and varied the role and importance of soil is in national economy and in life in general human society. So, soil protection and its rational use is one of the most important tasks of all humanity.

List of used literature

1. Alyamovsky N.I. Lime fertilizers in the USSR. / ed. A.V. Petersburgsky and S.G. Shederova, M., 1966. 476 p.

2. Bogdanov V.L., Kislyakova G.N. Reclamation soil science and agriculture. - M.: Kolos, 1992. - 224 p.

3. Kruglyakov M.Ya. etc. Integrated mechanization of fertilizer application. - M.: Kolos, 1972, 256 p.

4. Maukevich V.V., Lobanov P.P. Agricultural Encyclopedia: in 6 volumes/ - M.: Soviet Encyclopedia, 1974 - T.1-6.

5. Mirimanyan Kh.P. Soil science. - M.: Kolos, 1965. - 344 p.

6. Basics of farming: training manual/ ed. Prof. V.N. Prokosheva. - M.: Publishing house Kolos / 1975, 512 p.

7. Problems of agriculture: textbook / ed. S.G. Skoropanova. - M.: Publishing house Kolos / 1978, 296 p.

8. Khabarov A.V., Yaskin A.A. Soil science. - M.: Kolos, 2001. - 232 p.

Application.

Fig.1 Soil profile.

Fig.2 Soil profiles of some landscape zones.

Rice. 3 Soil map of the USSR.

Rice. 4 Soil map of Chuvashia.

SOILS AND ORGANIC WORLD OF LITHUANIA

Soil formation. The upper (up to 2 m) layer of loose rocks from which soils are formed is called soil-forming rocks. Soils in Lithuania were formed mainly on moraine loam, less often on sand and gravel. Young loams (formed during the last glaciation) contain greatest number carbonate substances (limestone particles).

Thus, the loams of the Musho-Nemunel lowland contain more than 20% carbonates, and the loams of the southern part of Lithuania contain three times less. In the Musho-Nyamunel lowland, carbonates occur at a depth of 60 cm, and in loams more than ancient origin– much deeper.

Soil types in Lithuania.

In that part of the Middle Lowland, where good natural drainage and moraine loams are rich in carbonates,

sod-carbonate soil. These are the most fertile soils in the republic, having a fairly thick (up to 30 cm) humus layer. They are located in small aral areas, since there are few areas of natural moisture on the plains.

In waterlogged areas, turf-gley soil. The fertility of these soils has recently increased markedly after drainage by closed drainage. Such soils are especially common on the moraine plains of the Middle Lowland.

These are the most common soils in Lithuania (occupying 45% of the entire territory). They are found on all hilly moraine hills.

Based on the severity of the soil horizon, soddy-podzolic soils are divided into weakly podzolized, moderately podzolized and strongly podzolized.

Lightly podzolized soddy-podzolic soils are more fertile than strongly podzolized soils. Heavily podzolized soddy-podzolic soils are located on the West Samogit Plateau, where more precipitation falls.

The soils of the plateau are less carbonate compared to the soils of the moraine plains of the Middle Lowland. In waterlogged places, podzolic soils become swamped and turn into podzolic-marsh (18% of the territory of Lithuania). Such soils are located on the slopes of the Samogitian Upland, along the outskirts of the lowlands and in the lowlands of the hilly terrain of the uplands.

The soils of the Southeast Plain were formed on layers of sand of varying grain sizes deposited by glacial meltwater. Melted glacial waters eroded moraine deposits, transported moraine materials and left sediments on the Dainava lowland, as well as on the lowland of the river. Neris and Zeimyans. A similar process occurs today, when alluvial sediments are formed in the floodplains of rivers. These sandy plains are characterized by podzolic boron soils found mainly in pine forests. These are the least fertile soils.

The surface of the ground in open forest is open to sun rays However, due to the infertility of the soil, grass grows poorly here and turf does not form. The forest floor consists mainly of lichens and moss; the top layer of soil underneath is light, whitish, reminiscent of ash in color. Soils with a peat layer thickness of more than 30 cm are called swampy. They are posted in small areas between other soil types and are more common on hilly moraine hills and sandy plains.

In the Nemunas delta and floodplain valleys of other rivers, alluvial soil. These are the most valuable soils of natural meadows. In the Nemunas delta they are drained.

Depending on the conditions of formation and properties of soils in Lithuania, there are 6 main types of soils:

1) podzolic: a) podzolic-pine forest, b) sod-podzolic;

2) podzolic-marsh;

3) sod-carbonate;

4) turf-gley;

5) swamp;

6) floodplain (or alluvial).

The soils of Lithuania were formed in mixed forests, where podzolization, turfing, waterlogging and other processes. Later, vast expanses of forest were converted into arable land and meadows, the grass cover of which contributed to turf.

Soil protection. Most of the surface of the republic is occupied by hilly hills, the topography of which is characterized by slopes of varying steepness. More gentle slopes are subject to water erosion, which covers almost half of the soils of the hilly moraine hills. Various measures are taken to protect these soils: sowing perennial herbs, cultivated meadows are being planted. Soils on steeper (more than 15°) slopes that are highly susceptible to erosion are not susceptible to machining, that's why forests are planted here.

SOIL PODZOLIZATION

The process of removal of clay particles, iron and aluminum oxides, alkaline soils and alkalis from the upper soil horizons, leading to a decrease in the fertility of these horizons and the accumulation of quartz in them. The main conditions for the manifestation of podzolization of soils are: a humid climate, which determines the leaching regime of the soil, during which the mobile products of soil formation occur, and forest vegetation, leading to the formation of acidic organic substances, causing the destruction of the mineral part of the soil.

WATERWASHING OF SOIL

- soil-forming process leading to excessive soil moisture. It begins with a change in the water-air regime, the accumulation of moisture and the emergence of anaerobic conditions in the soil. It is expressed in the appearance of signs of gleying and in the accumulation of semi-decomposed plant remains of peat. Soil waterlogging can be caused by groundwater, slope water or precipitation.

The diversity of soils on the earth's surface is very great, which is due to the history of soil formation and the variety of combinations of soil formation factors: rocks, vegetation, etc.

The distribution of the main types of soils can be found on the soil map in geographical atlases.

Arctic soils are formed in the Far North, where the soil is frozen almost all year round. Rare mosses and lichens practically do not provide organic matter for the formation of humus, so the humus horizon does not exceed 1 cm.

Tundra soils are a set of soils in the tundra zone of the Northern Hemisphere. Tundra soils are thin, contain up to 5% humus, often with signs of permafrost phenomena.

Podzolic soils are the soils of taiga and mixed forests.

Podzolic soils are formed under continental and temperate continental climates with excess moisture and constant leaching by infiltrating waters. They contain little humus (1-4%), are not fertile, and require fertilization. Distributed in the Russian Federation, in the countries of Northern and Central Europe, Canada, and the northeastern United States. IN podzolic soils The podzolic horizon is well defined, from which particles of humus, clay particles, iron oxides, etc. are washed out, the deposition of which occurs in the lower, illuvial horizon. In mixed forests, where there are more grasses in the forest floor, the humus horizon is better developed, and soddy-podzolic soils are formed there.

Brown forest soils are a type of soil in broad-leaved and coniferous-deciduous forests in a warm-temperate, humid climate. Brown forest soils contain 5-10% humus, have a brown color due to the accumulation of clay minerals and iron oxides in all horizons, are usually slightly acidic, and have good structure. Brown forest soils are common in Western, Central and Eastern Europe, in the Caucasus, the Far East of the Russian Federation, as well as in China, Korea, and the USA.

Chernozems - soils of forest-steppe and steppe zones temperate zone, are richest in humus, the content of which is 6-9%, which is why the soils have an intense black or brown-black color. The thickness of the humus horizon is from 40 to 120 cm. Organic matter accumulates in the upper part of the profile, the illuvial horizon is enriched with calcium. Chernozems are common in Russia, Western and South-Eastern Europe, Kazakhstan, China, USA, Canada, Argentina, and Chile.

Chestnut soils are soils of dry steppes and semi-deserts of the temperate zone. The humus horizon of chestnut soils is less thick than that of chernozems (humus content 1.5-4.5%), which explains the lighter (dark chestnut, chestnut and light chestnut) color of the soils. Organic matter is replenished by abundant grass cover, which develops over a short period of time as long as there is sufficient moisture in the soil after winter.

Chestnut soils are quite fertile, but require irrigation. They occupy significant areas in the south of Ukraine, the Russian Federation, Northern Mongolia, China, Turkey, the USA, and Argentina.

Gray soils are soils of semi-deserts and deserts of the subtropical zone. Gray soils are characteristic of foothills and piedmont plains composed of loess. They are weakly divided into horizons: at the top there is a light gray humus horizon, at the bottom there is a compacted carbonate illuvial horizon. The parent rock (loess) often contains gypsum. Humus in light gray soils is 1-1.5%, in dark ones - 2.5-4.5%. Humus, as in other arid areas, accumulates mainly due to spring herbaceous vegetation.

In general, gray soils have good water permeability and other properties favorable for agriculture and are fertile with sufficient irrigation. Distributed in Central and Western Asia, North America, Australia.

In tropical latitudes, red-yellow, red, red-brown and brown-red soils are common. The reddish color is due to the high content of iron, aluminum and manganese oxides formed as a result of chemical weathering.

Mountain soils are a group of soils formed in mountainous terrain. Most mountain soils are characterized by gravelly, low thickness and richness in primary minerals, which is primarily due to the position of these soils on slopes of considerable steepness.

The distribution of mountain soils is subject to altitudinal zonation: depending on changes in climatic conditions with height, on the latitudinal and sectoral position of the mountains, and the exposure of slopes, mountain-tundra, mountain-taiga, mountain-meadow, mountain meadow-steppe, mountain-steppe and other soils are formed.

Meadow soils are a type of soil that forms under meadow vegetation under conditions of increased surface moisture and/or constant connection with groundwater. Meadow soils are characterized by the presence of a gley horizon in the lower part of the profile, a well-developed humus horizon, and are often saline and carbonate.

Swamp soils are soils formed under conditions of prolonged or constant excess moisture (swamping) under moisture-loving vegetation. Typically, bog soils form in the forest zone of temperate zones. After drainage, crops are grown on the swamp soils and peat is extracted. Swamp soils are common in the Russian Federation, Belarus, Ukraine, Canada, USA, Brazil, Argentina, Indonesia, etc. Swamp soils are divided into peat and peat-gley soils.

Saline soils are soils in arid zones with a high (more than 0.25%) content of easily soluble mineral salts in water: chlorides, sulfates, sodium carbonates, calcium and magnesium.

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In Russia there are several main types of soils, which are located in different natural areas and differ from each other in a number of characteristics. What soils are the most fertile and how many types of soils are found in our country?

What is soil?

Soil is a natural formation that has fertility and is created under the influence of rocks, climate, vegetation, wildlife, relief, human activity and the geological age of the territory. The process of soil formation takes centuries and millennia. It begins with the destruction of rocks and the simplest organisms in them, which prepare conditions for plants and animals. Dead remains of plants and animals under the influence of microorganisms turn into humus (humus), which is capable of holding together mineral soil particles into lumps of different sizes. The soil has a number of properties: color, humidity, mechanical composition, structure, density, presence of inclusions.

Rice. 1. Humus.

Clay, sand, silt are the main components of the soil layer.

As the soil develops, its profile is divided into horizons - approximately homogeneous layers interconnected with each other. At the top there is a humus horizon, in which the basic substances necessary for plant nutrition accumulate. Below is a leaching horizon, poor in nutrients, then a leaching horizon that passes into the parent rock.

Rice. 2. Arctic soils.

Soil types in Russia

In Russia, soils are diverse. The main types found in our state include:

• tundra gley soils – a distinctive feature of these soils is their low humus content and high acidity. They are located south of the Arctic soils in permafrost areas.
• arctic soils – this type of soil is formed during the process of thawing permafrost. The fertile layer is no more than 2 cm. These soils are not restored and due to the harsh climate there is no vegetation on them.
• podzolic soils – a soil type characteristic of forests with a humus content of up to 4%. Due to exposure to acid, these soils are called acidic. To obtain a stable harvest, the soil must be fertilized and properly cultivated.
• gray forest soils – are formed in deciduous forests exclusively with a continental climate. Due to the calcium contained in the soil, water does not penetrate inside and does not erode it. Fertility is average, since the humus layer does not exceed 8%.
• brown forest soils – soils are common in forests temperate climate. The fertile layer is 30 cm, followed by a layer of clay of 20-40 cm. The main subtypes: podzolized, typical, gley.
• chestnut soils - common in natural areas such as steppes and semi-deserts. The fertile layer reaches 4.5%, which is an indicator of average soil fertility.

The first scientist who proposed a classification of soils was V.V. Dokuchaev

Rice. 3. V.V. Dokuchaev.

Do you apply fertilizers, apply pesticides, water and loosen, from morning until late at night in the beds, but the harvest is not pleasing? Are you spending money on zoned modern varieties and hybrids, but as a result there are pathetic, diseased plants on the site? Maybe it's all about the soil?

Gardening and horticulture are aimed at obtaining good harvests. Suitable plant varieties, timely use of fertilizers and pesticides, watering - all this affects the final result.

But correct agricultural technology gives the desired result only when taking into account the characteristics of the soil in a given area. Let's understand the types and types of soil, their pros and cons.

Soil types are classified according to their content:

• minerals (main part);
• organic matter and, first of all, humus, which determines its fertility;
• microorganisms and other living beings involved in the processing of vegetation residues.

An important quality of soil is the ability to pass air and moisture, as well as the ability to retain incoming water.

For a plant, such a soil property as thermal conductivity (also called heat capacity) is extremely important. It is expressed in the period of time during which the soil is able to heat up to a certain temperature and, accordingly, give off heat.

The mineral part of any soil is sedimentary rocks formed as a result of weathering of rock formations. Over millions of years, water flows separate these products into two types:

• sand;
• clay.

Another mineral-forming species is limestone.

As a result, 7 main types of soils can be distinguished for the flat part of Russia:

• clayey;
• loamy (loam);
• sandy;
• sandy loam (sandy loam);
• limestone;
• peat;
• chernozem.

Soil characteristics

Clayey

Heavy, difficult to process, take a long time to dry and warm up slowly in the spring. They do not allow water and moisture to reach plant roots well. In such soil, beneficial microorganisms develop poorly, and there is practically no process of decomposition of plant residues.

Loamy

One of the most common soil types. In terms of quality, they are second only to black soils. Suitable for growing all garden and vegetable crops.

Loams are easy to process and have normal acidity. They heat up quickly, but do not immediately release the stored heat.

A good environment for the development of underground microflora. The processes of decomposition and rotting, due to the access of air, proceed intensively.

Sandy

Easy for any processing, they allow water, air and liquid fertilizers to reach the roots well. But these same qualities also have negative consequences: the soil quickly dries out and cools down, fertilizers are washed away by water during rains and watering and go deep into the soil.

Sandy loam

Possessing everyone positive qualities Sandy soils, sandy loam better retain mineral fertilizers, organic matter and moisture.

Limestone

The soil is not suitable for gardening. It is low in humus, as well as iron and manganese. An alkaline environment requires acidification of the calcareous soil.

Peat

Areas in swampy areas need cultivation and, above all, reclamation work. Acidic soils must be limed annually.

Chernozem

Chernozem is a standard soil and does not require cultivation. Proper agricultural technology is all that is needed to grow a rich harvest.

For a more accurate classification of soil, its main physical, chemical and organoleptic parameters are considered.

Soil type characteristics	clayey	loamy	sandy	sandy loam	limestone	peat	black soil
Structure	Large blocky	lumpy, structural	Fine grain	Finely lumpy	rocky inclusions	loose	Granular-lumpy
Density	high	average	low	average	high	low	average
Breathability	Very low	average	high	average	low	high	high
Hygroscopicity	low	average	low	average	high	high	high
Heat capacity (heating rate)	low	average	high	average	high	low	high
Acidity	Slightly acidic	Neutral to acidic	Low, close to neutral	slightly acidic	alkaline	sour	From slightly alkaline to slightly acidic
% humus	Very low	Medium, closer to high	short	average	short	average	high
Cultivation	Adding sand, ash, peat, lime, organic matter.	Maintain the structure by adding manure or humus.	Adding peat, humus, clay dust, planting green manure.	Regular addition of organic matter, autumn sowing green manure	Application of organic, potassium and nitrogen fertilizers, ammonium sulfate, sowing green manure	Adding sand, abundant liming, manure, compost.	When depleted, add organic matter, compost, and sow green manure.
Crops that can grow	trees and shrubs with a developed root system going deep into the soil: oak, apple trees, ash	Almost all zoned varieties grow.	Carrots, onions, strawberries, currants	Most crops grow when correct agricultural technology and zoned varieties are used.	Sorrel, lettuce, radish, blackberry.	Currants, gooseberries, chokeberries, garden strawberries	Everything grows.

Main soil types in Russia

More than a hundred years ago V.V. Dokuchaev discovered that the formation of the main types of soils on the Earth's surface follows the law of latitudinal zonation.

Soil type is its attributes that arise in similar conditions and have the same parameters and conditions of soil formation, which in turn depend on the climate during geological significant periods time.

The following soil types are distinguished:

• tundra;
• podzolic;
• sod-podzolic;
• forest gray;
• black earth;
• chestnut;
• brown.

The tundra and brown soils of semi-deserts are completely unsuitable for agriculture. Podzolic taiga and chestnut soils of dry steppes are infertile.

For agricultural activities, the main importance is medium-fertile sod-podzolic soil, fertile gray forest soil and maximally fertile chernozem soil. Humus content, climatic conditions With necessary warmth and moisture make these soils attractive for working on them.

We are used to seeing beauty in the clouds, in the surrounding nature, and never in the soil. But it is she who creates those unique pictures that remain in the memory for a long time. Love, get to know and take care of the soil on your site! She will repay you and your children with wonderful harvests, the joy of creation and confidence in the future.

Determination of soil mechanical composition:

The importance of soil in the life of mankind: