Soil types in Russia. What are the soils and natural zones Table by geography natural zone soil types

Natural zones, replacing each other from the poles to the equator, differ in soil types.

Polar zone (zone of arctic deserts). The Arctic land is the islands and narrow sections of the continental coasts of Asia and North America.

The most common type of automorphic soils in the Arctic is arcto-tundra soils. The thickness of the soil profile of these soils is determined by the depth of seasonal thawing of the soil-ground layer, which rarely exceeds 30 cm.In the soils formed under the most favorable conditions, only the vegetative-peaty horizon (A 0) is well expressed and the thin humus horizon (A1) is much worse. ... In arcto-tundra soils, due to excessive atmospheric moisture and a high-lying surface of permafrost, high humidity is constantly maintained during a short season of positive temperatures. Such soils have a weak acidic or neutral reaction (pH from 5.5 to 6.6) and contain 2.5–3% humus. In relatively fast drying areas with a large number of flowering plants, soils are formed with a neutral reaction and an increased humus content (4–6%).

Salt accumulation is characteristic of the landscapes of the arctic deserts. Salt efflorescence is frequent on the soil surface, and in summer, as a result of salt migration, small brackish lakes can form.

Tundra (subarctic) zone. On the territory of Eurasia, this zone occupies a wide strip in the north of the continent, most of it is located beyond the Arctic Circle, however, in the northeast of the continent, tundra landscapes extend much further south, reaching the northeastern part of the coast of the Sea of ​​Okhotsk. In the Western Hemisphere, the tundra zone covers almost all of Alaska and a vast area of ​​northern Canada. Tundra landscapes are common on the southern coast of Greenland, Iceland, on some islands Barents Sea... In some places, tundra landscapes are found in the mountains above the border of the forest.

Above the surface of permafrost strata, tundra-gley soils are widespread; they are formed under conditions of difficult drainage of soil and groundwater and oxygen deficiency. They, as well as other types of tundra soils, are characterized by the accumulation of weakly decomposed plant residues, due to which there is a well-defined peaty horizon (At) in the upper part of the profile. Below the peaty horizon there is a thin (1.5–2 cm) humus horizon ( A 1) brownish brown. Further, there is a gley soil horizon of a specific bluish-gray color, which is formed as a result of recovery processes under conditions of water saturation of the soil layer. The gley horizon extends to the upper surface of the permafrost.

Now, in connection with the active development of the mineral resources of the North, the problem of protecting the nature of the tundra, and, first of all, its soil cover, has arisen. The upper peaty horizon of tundra soils is easily disturbed and takes decades to recover. Traces of vehicles, drilling and construction machines cover the surface of the tundra, contributing to the development of erosion processes. The disturbance of the soil cover causes irreparable damage to the entire unique nature of the tundra. Strict control of economic activity in the tundra is a difficult, but extremely necessary task.

Taiga zone. Taiga forest landscapes form a vast belt in the northern hemisphere, stretching from west to east in Eurasia and North America.

In the absence of permafrost, different types of podzolic soils are formed on well-permeable sandy and sandy loam soil-forming rocks. The profile structure of these soils:

A 0 - forest litter, consisting of needles litter, the remains of trees, shrubs and mosses, which are at different stages of decomposition. The thickness of this horizon is from 2–4 to 6–8 cm. The reaction of the forest litter is strongly acidic (pH = 3.5–4.0). And 2 - eluvial horizon (washout horizon), from which all more or less mobile connections are taken out to the lower horizons. In these soils, this horizon is called podzolic. . Sandy, easily crumbling, due to washing out of a pale gray, almost white color. Despite its small thickness (from 2–4 cm in the north and in the center to 10–15 cm in the south of the taiga zone), this horizon stands out sharply in the soil profile due to its color.

B - a bright brown, coffee or rusty-brown illuvial horizon, in which erosion prevails, i.e. precipitation of compounds of those chemical elements and small particles that were washed out from the upper part of the soil layer (mainly from the podzolic horizon). With depth in this horizon, the rusty-brown hue decreases and gradually passes into the parent rock. The thickness is 30–50 cm.

C - parent rock, represented by gray sand, gravel and boulders.

The thickness of the profile of these soils gradually increases from north to south. The soils of the southern taiga have the same structure as the soils of the northern and middle taiga, but the thickness of all horizons is greater.

In Eurasia, podzolic soils are common only in the part of the taiga zone west of the Yenisei. In North America, podzolic soils are common in the southern part of the taiga zone. The territory east of the Yenisei in Eurasia (Central and Eastern Siberia) and the northern part of the taiga zone in North America (northern Canada and Alaska) are characterized by continuous permafrost, as well as features of the vegetation cover. Acid brown taiga soils (podburs) are formed here, sometimes referred to as permafrost-taiga ferruginous soils.

From a medico-geographical point of view, the taiga forest zone is not very favorable, since as a result of intensive soil leaching, many chemical elements are lost, including those necessary for the normal development of humans and animals, therefore, conditions for a partial deficiency of a number of chemical elements are created in this zone ( iodine, copper, calcium and etc.)

Mixed forest zone. To the south of the taiga forest zone, there are mixed coniferous-deciduous forests. In North America, these forests are common in the east of the mainland in the Great Lakes region. in Eurasia - on the territory of the East European Plain, where they form a wide zone. Beyond the Urals, they continue far to the east, up to the Amur region, although they do not form a continuous zone.

The mixed forest zone has a rather variegated soil cover. The most typical type of automorphic soils of mixed forests of the East European Plain are sod-podzolic soils – southern variety of podzolic soils. Soils are formed only on loamy soil-forming rocks. Sod-podzolic soils have the same structure of the soil profile as podzolic soils. They differ from podzolic ones by a lesser thickness of the forest litter (2–5 cm), a greater thickness of all horizons, and a more pronounced humus horizon A1, which lies under the forest litter. The appearance of the humus horizon of sod-podzolic soils also differs from the horizon in podzolic soils, in the upper part it contains numerous grass roots, which often form a well-defined sod. Color - various shades of gray, loose constitution. The thickness of the humus horizon is from 5 to 20 cm, the humus content is 2–4%.

In the upper part of the profile, these soils are characterized by an acidic reaction (pH = 4); with depth, the reaction gradually becomes less acidic.

The use of mixed forest soils in agriculture is higher than that of taiga forests. In the southern regions of the European part of Russia 30–45% of the area is plowed up, in the north the share of plowed lands is much less. Agriculture is difficult due to the acidic reaction of these soils, their strong leaching, and in places swampy and boulders. To neutralize excess acidity, the soil is lime. To obtain high yields, large doses of organic and mineral fertilizers are needed.

Deciduous forest zone. In the temperate zone, in warmer conditions (compared to taiga and subtaiga mixed forests), broad-leaved forests with rich grass cover are widespread. In North America, the broadleaf forest zone extends in the east of the continent to the south of the mixed forest zone. In Eurasia, these forests do not form a continuous zone, but stretch in discontinuous stripes from Western Europe to the Primorsky Territory of Russia.

Among the soils formed in these landscapes, two types are distinguished:

1. Gray forest soils formed in the inland regions (central regions of Eurasia and North America). In Eurasia, these soils stretch as islands from the western borders of Belarus to Transbaikalia.

Soil-forming rocks are mainly cover loess-like loams.

Profile structure of gray forest soil:

A 0 - forest litter of tree and grass litter, usually of low thickness (3-5 cm);

А 1 - humus horizon of gray or dark gray color, lumpy-powdery structure, containing a large number of grass roots.

А 1 А 2 - humus-eluvial horizon, lighter colored with a lumpy structure.

А 2 В - eluvial-illuvial horizon, grayish-brownish or grayish-brown in color, with a clearly expressed angular-fine-peaked structure.

B - eluvial, dense, brown-brown, with a nutty or prism-nutty well-defined structure. According to the severity of morphological features, it is subdivided into horizons B 1 and B 2.

BC - transitional from illuvial to parent rock differs in less clear structuredness, less dense constitution.

The type of gray forest soils is divided into three subtypes- light gray, gray and dark gray, the names of which are associated with the intensity of the color of the humus horizon.

Gray forest soils are much more fertile than sod-podzolic soils, they are favorable for growing grain, fodder, horticultural and some industrial crops. The main disadvantage is greatly reduced fertility as a result of centuries of their use and significant destruction as a result of erosion.

2. Brown forest soils formed in areas with a mild and humid oceanic climate, in Eurasia - Western Europe, the Carpathians, the Mountainous Crimea, warm and humid regions of the Caucasus and the Primorsky Territory of Russia, In North America - the Atlantic part of the continent.

The profile of brown forest soils is characterized by a poorly differentiated and thin not very dark humus horizon and consists of the following genetic horizons A 0 –A 0 A 1 –A 1 - B t (B t, I, h, f) –BC – C.

A 0 - forest litter of leaf litter, needles and grit residues, with a thickness of 0.5 to 5 cm.

A 0 A 1 - deep-humus humus horizon of dark gray color, loose.

А 1 - humus horizon of darkish-brown or gray-brown color, loose-lumpy or lumpy-granular structure, loamy sometimes with rubble inclusions. The thickness is 10–20 cm.

In t, I, h, f - a metamorphic horizon of brown or brown-brown color, clayey, sometimes compacted, with a lumpy-nutty or granular-nutty structure.

ВС - horizon transitional to the rock.

C - the parent rock is represented by loamy stony-crushed eluvium and eluvial-diluvium of dense rocks and, much less often, fine-earth rocks.

With a large amount of applied fertilizers and rational agricultural technology, these soils give very high yields of various agricultural crops, in particular, the highest yields of grain crops are obtained on these soils. In the southern regions of Germany and France, brown soils are mainly used for vineyards.

Zone of meadow steppes, forest-steppes and meadow-forb steppes. In Eurasia, to the south of the zone of deciduous forests, there is a zone of forest-steppe, which is replaced even further south by a zone of steppes. Automorphic soils of landscapes of meadow steppes of the forest-steppe zone and meadow-forb steppes of the steppe zone are called chernozems .

Soil-forming rocks of the territory of chernozems are represented mainly by loess-like deposits (loess is a fine-grained sedimentary rock of light yellow or fawn color).

The most characteristic feature of these soils, which gave rise to their name, is a powerful, well-developed humus horizon of intense black color.

Profile structure of typical chernozems:

A - humus horizon, uniformly dark-colored horizon with granular structure.

AB - humus dark-colored with general russeting downward or non-uniformly colored with alternating dark humous areas and dark brown, gray-brown spots or wedges, granular structure.

B - transitional to the breed, has a predominantly brown uneven color, gradually turning into the color of the parent rock. According to the degree, form of humus content and structure, they can be subdivided into B 1 -B 2.

Accumulation of carbonates is observed in the ВС к horizon and the С к source rock.

Chernozems are famous for their fertility, the areas of their distribution are the main base for the production of many cereals, primarily wheat, as well as a number of valuable industrial crops (sugar beets, sunflowers, corn). The yield on chernozems depends mainly on the water content in the form available to the plant. In our country, the black earth regions were characterized by crop failures caused by droughts.

The second equally important problem of chernozems is soil destruction caused by erosion. On the chernozem soils used for agriculture, special anti-erosion measures are required.

Zone of dry steppes and semi-deserts of the temperate zone. To the south of the steppe zone, there is a semi-desert zone. The southern steppes (they are called dry steppes), bordering on semi-deserts, differ significantly in vegetation cover and soils from the northern steppes. In terms of vegetation and soils, the southern steppes are closer to semi-deserts than to steppes.

In arid and extracontinental conditions of dry steppes and semi-deserts, chestnut and brown desert-steppe soils, respectively, are formed.

In Eurasia chestnut soils occupy a small area in Romania and are more widely represented in the arid central regions of Spain. They stretch in a narrow strip along the coast of the Black and Azov Seas. To the east (in the Lower Volga region, the Western Caspian region), the area of ​​these soils increases. Chestnut soils are very widespread on the territory of Kazakhstan, from where a continuous strip of these soils goes to Mongolia, and then to Eastern China, occupying most of the territory of Mongolia and the central provinces of China. In Central and Eastern Siberia, chestnut soils are found only as islands. The easternmost area of ​​distribution of chestnut soils is the steppes of Southeastern Transbaikalia.

Spreading brown desert-steppe soils more limited - these are mainly semi-desert regions of Kazakhstan.

In North America, chestnut and brown soils are located in the central part of the continent, bordering the black earth zone in the east, and rocky mountains in the west. In the south, the area of ​​distribution of these soils is limited to the Mexican plateau.

Loess-like loams occurring on rocks of different composition, age and origin are the parent rocks.

Profile structure of chestnut and brown soils:

A - humus horizon. In chestnut soils, it is grayish-chestnut in color, saturated with plant roots, a lumpy structure and has a thickness of 15-25 cm. In brown soils, it is brown, with a lumpy fragile structure, about 10-15 cm thick. The humus content in this horizon is from 2 to 5 % in chestnut soils and about 2% in brown soils.

B - brown-brown transitional horizon, compacted, below there are carbonate new formations. The thickness is 20–30 cm.

C - parent rock, represented by yellowish-brown loess-like loam in chestnut soils and brownish-fawn in brown soils. In the upper part, there are carbonate new formations. Below 50 cm in brown soils and 1 m in chestnut soils, gypsum neoplasms are found.

Among chestnut soils, there are three subtypes, replacing each other from north to south:

Dark chestnut, having a humus horizon thickness of about 25 cm or more, chestnut with a humus horizon thickness of about 20 cm and light chestnut, with a thickness of the humus horizon of about 15 cm.

A characteristic feature of the soil cover of dry steppes is its extraordinary variegation, this is due to the redistribution of heat and microrelief by forms of meso- and micro-relief, and especially moisture, and with it water-soluble compounds. Lack of moisture is the reason for a very sensitive reaction of vegetation and soil formation even to a slight change in moisture. Zonal automorphic soils (i.e. chestnut and brown desert-steppe soils) occupy only 70% of the territory, the rest falls on saline hydromorphic soils (salt licks, salt marshes, etc.).

Desert zone. In Eurasia, a desert zone stretches south of the semi-desert zone. It is located in the inland part of the continent - on the vast plains of Kazakhstan, Central and Central Asia. Zonal automorphic desert soils are gray-brown desert soils.

Loess-like and ancient alluvial deposits, processed by the wind, prevail among the parent rocks.

Gray-brown soils are formed on elevated flat areas of the relief. A characteristic feature of these soils is the accumulation of carbonates in the upper part of the soil profile, which looks like a surface porous crust.

Profile structure of gray-brown soils:

And to - carbonate horizon, it is a surface crust with characteristic rounded pores, cracked into polygonal elements. The thickness is 3–6 cm.

A - a weakly expressed humus horizon of gray-brown color, in the upper part weakly fastened by roots, loose downward, easily fluttering by the wind. The thickness is 10–15 cm.

B - transitional, compacted brown horizon, prism-like-blocky structure, containing rare and poorly expressed carbonate formations. Thickness is from 10 to 15 cm.

C - parent rock - loose loess-like loam overflowing with small crystals of gypsum. At a depth of 1.5 m and below, a kind of gypsum horizon often occurs, represented by clusters of vertically arranged needle-like gypsum crystals. The thickness of the gypsum horizon is from 10 cm to 2 m.

The characteristic hydromorphic soils of deserts are salt marshes , those. soils containing 1% or more water-soluble salts in the upper horizon. Most of the salt marshes are distributed in the desert zone, where they occupy about 10% of the area. In addition to the desert zone, salt marshes are quite widespread in the zone of semi-deserts and steppes, they are formed when the groundwater is close to the ground and the effusion water regime. The salt-containing groundwater reaches the soil surface and evaporates; as a result, salts are deposited in the upper soil horizon and salinization occurs.

Soil salinization can occur in any zone under sufficiently arid conditions and the proximity of groundwater, as evidenced by the salt marshes in the arid regions of the taiga, tundra and arctic zones.

Rice. 9.1. Fanning cones (proluvial plumes) in the deserts of Turkmenistan.

Subtropical zone. In this climatic zone, the following main groups of soils are distinguished: soils of moist forests, dry forests and shrubs, dry subtropical steppes and low-grass semi-savannas, as well as subtropical deserts.

1. Red and yellow soils landscapes of humid subtropical forests

These soils are widespread in subtropical East Asia (China and Japan) and in the southeastern United States (Florida and neighboring southern states). They are also found in the Caucasus - on the coast of the Black (Adjara) and Caspian (Lankaran) seas.

Characteristic type soils of humid subtropics - red earth, named for their color, due to the composition of the parent rocks. The main parent rock on which red soils develop is a layer of redeposited weathering products of a specific brick-red or orange color. This color is due to the presence of strongly bound Fe (III) hydroxides on the surface of clay particles. The red earths inherited from the parent rocks not only color, but also many other properties.

Soil profile structure:

A 0 - poorly decomposed forest litter, consisting of leaf litter and thin branches. The thickness is 1–2 cm.

А 1 - a gray-brown humus horizon with a reddish tint, with a large number of roots, a lumpy structure and a thickness of 10–15 cm. The humus content in this horizon is up to 8%. Down the profile, the humus content decreases rapidly.

B - transitional horizon of brownish-red color, the red tint intensifies downward. Dense, lumpy structure, along the paths of dead roots, streaks of clay are visible. The thickness is 50-60 cm.

C - parent rock of red color with whitish spots, clay pellets are found, there are small ferromanganese nodules. Films and streaks of clay are noticeable in the upper part.

Krasnozems are characterized by an acidic reaction of the entire soil profile (pH = 4.7–4.9).

Yellow soils are formed on clay shales and clays with poor water permeability, as a result of which gleying processes develop in the surface part of the profile of these soils, which cause the formation of oxide-ferruginous nodules in the soils.

The soils of humid subtropical forests are poor in nitrogen and some ash elements. To increase fertility, organic and mineral fertilizers are needed, primarily phosphates. The development of soils in humid subtropics is complicated by strong erosion that develops after deforestation; therefore, the agricultural use of these soils requires anti-erosion measures.

2. Brown soils landscapes of dry subtropical forests and shrubs

The soils, called brown soils, formed under dry forests and shrubs, are widespread in southern Europe and northwest Africa (Mediterranean region), southern Africa, the Middle East, and several regions of Central Asia. Such soils are found in warm and relatively dry regions of the Caucasus, on the southern coast of Crimea, in the Tien Shan mountains. In North America, soils of this type are common in Mexico; under dry eucalyptus forests, they are known in Australia.

Brown soils formed under dry forests of various species composition. In the Mediterranean, for example, these are forests of evergreen oak, laurel, seaside pine, treelike juniper, as well as dry shrubs such as shibliak and maquis, hawthorn, hold-tree, fluffy oak, etc.

Profile structure of brown soils:

А 1 - humus horizon of brown or dark brown color, lumpy structure, si, 20–30 cm thick. The humus content in this horizon is 2.0–2.4%. Down the profile, its content gradually decreases.

B - a compacted transitional horizon of bright brown color, sometimes with a reddish tint. This horizon often contains new carbonate formations, in relatively humid regions they are located at a depth of 1–1.5 m, in arid regions they may already be in the humus horizon.

C - parent rock.

D - with a small thickness of the parent rock below the transitional horizon, there is a soil underlying rock (limestone, shale, etc.).

The reaction of soils in the upper part of the profile is close to neutral (pH = 6.3), in the lower part it becomes slightly alkaline.

The soils of subtropical dry forests and shrubs are highly fertile and have been used for a long time for agriculture, including viticulture, olive and fruit trees. Deforestation to expand cultivated land, combined with mountainous terrain, has contributed to soil erosion. So in many Mediterranean countries, the soil cover was destroyed and many areas that once served as the granaries of the Roman Empire are now covered with desert steppes (Syria, Algeria, etc.).

3. Dry gray soils subtropics

In the arid landscapes of the semi-deserts of the subtropical belt, serozems are formed , they are widely represented in the foothills of the ranges of Central Asia. They are distributed in the north of Africa, in the continental part of the south of North and South America.

Forests are predominantly soil-forming rocks.

Profile structure of sierozem:

A - light gray humus horizon, noticeably sodden, unclear lumpy structure, 15–20 cm thick. The amount of humus in this horizon is about 1.5–3%; down the profile, the humus content decreases gradually.

А / В - intermediate horizon between humus and transitional horizons. Loosener than humus, thickness - 10-15 cm.

B - brownish-fawn transitional horizon, poorly compacted, contains carbonate new formations. At a depth of 60–90 cm, gypsum neoplasms begin. It passes to the parent rock gradually. The thickness is about 80 cm.

C - parent rock

The entire profile of gray soils bears traces of intensive activity of earthmoving - worms, insects, lizards.

The serozem soils of the semi-deserts of the subtropical zone are bordered by the gray-brown soils of the deserts of the temperate zone and are associated with them by gradual transitions. However, typical serozem soils differ from gray-brown soils in the absence of a surface porous crust, a lower carbonate content in the upper part of the profile, a significantly higher humus content, and a lower location of gypsum neoplasms.

In gray soils there is a sufficient amount of chemical elements necessary for plant nutrition, with the exception of nitrogen. The main difficulty in their agricultural use is associated with the lack of water; therefore, irrigation is important for the development of these soils. Thus, rice and cotton are cultivated on irrigated gray soils in Central Asia. Farming without special irrigation is possible mainly in elevated areas of the foothills.

Tropical zone. The tropics here means the territory between the northern and southern tropics, i.e. parallels with latitudes. This territory includes tropical, subequatorial and equatorial climatic zones.

Tropical soils occupy more than 1/4 of the world's land surface. The conditions of soil formation in the tropics and countries of high latitudes are sharply different. The most notable distinctive features of tropical landscapes are climate, flora and fauna, but these differences are not limited to.

The red-colored sediments have a sandy-loamy composition, their thickness varies from several decimeters to 10 m or more. These deposits were formed in rather humid conditions, favorable for the high geochemical activity of iron. These deposits contain iron oxide, which gives the deposits a red color.

Along with red-colored sediments, lacustrine loams with a gray color, light yellow sandy loam alluvial deposits, brown volcanic ash, etc. can act as parent rocks; therefore, soils formed under the same bioclimatic conditions are not always the same color.

1. Soils of landscapes rainforests (constantly humid) tropical forests

Constantly humid tropical forests are spread over a large area in South America, Africa, Madagascar, Southeast Asia, Indonesia, the Philippines, New Guinea and Australia. Soils are formed under these forests, for which different names have been proposed at different times - red-yellow lateritic, ferralite and etc.

The humus horizon of the rain forest soil is gray, very thin (5–7 cm) and contains only a few percent of humus. It is replaced by the transitional horizon A / B (10–20 cm), during which the humus hue completely disappears.

The peculiarity of these biocenoses is that almost the entire mass of chemical elements necessary for plant nutrition is contained in the plants themselves and only because of this is not washed out by abundant atmospheric precipitation. When the rainforest is cleared, atmospheric precipitation very quickly erodes the upper thin fertile soil layer and barren lands remain under the cleared forest.

2. Soils of tropical landscapes seasonal atmospheric humidification

Light tropical forests are characterized by the free arrangement of trees, an abundance of light and, as a result, a lush cover of grasses. High-grass savannas are various combinations of grassy vegetation with islands of forest or individual specimens of trees. The soils forming under these landscapes are called red or ferralitic soils of seasonally humid tropical forests and tall grass savannas

The profile structure of these soils:

Above there is a humus horizon (A), in the upper part it is more or less soddy, 10–15 cm thick, dark gray in color. Below is the transitional horizon (B), during which the gray shade gradually disappears and the red color of the parent rock intensifies. The thickness of this horizon is 30–50 cm. The total humus content in the soil is from 1 to 4%, sometimes more. The reaction of soils is slightly acidic, often almost neutral.

These soils are widely used in tropical agriculture. The main problem with their use is the easy destruction of soils under the influence of erosion.

With the duration of the dry period from 7 to 10 months a year and the annual precipitation amount of 400–600 mm, xerophytic biocenoses develop, which are a combination of dry tree and shrub thickets and low grasses. The soils forming under these landscapes are called reddish-brown soils of dry savannas.

The structure of these soils:

Under the humus horizon A, about 10 cm thick, of a slightly gray shade, there is a transitional horizon B, 25–35 cm thick. In the lower part of this horizon, sometimes there are carbonate concretions. This is followed by the parent rock. The humus content in these soils is usually low. The reaction of the soils is slightly alkaline (pH = 7.0–7.5).

These soils are widespread in the central and western regions of Australia, in some areas of tropical Africa. They are of little use for agriculture and are mainly used for pastures.

With an annual precipitation of less than 300 mm, soils are formed arid tropical (semi-desert and desert) landscapes, having common features with gray-brown soils and gray soils. They have a thin and poorly differentiated carbonate profile. Since the parent rocks in many regions are red products of [Neogene] weathering, these soils are reddish in color.

Tropical Islands Zone. A special group is formed by the soils of the oceanic islands of the tropical belt of the World Ocean, among them the most peculiar are the soils of coral islands - atolls.

White coral sands and reef limestones serve as the parent rock on these islands. The vegetation is represented by thickets of shrubs and forests of coconut trees with an intermittent cover of low grasses. Here the most common atoll humus-calcareous sandy soils with a thin humus horizon (5–10 cm), characterized by a humus content of 1–2% and a pH of about 7.5.

Often important factor Soil formation on the islands is the avifauna. Colonies of birds deposit huge amounts of droppings, which enrich the soil with organic matter and contribute to the emergence of special woody vegetation, thickets of tall grasses and ferns. A powerful peat-humus horizon with an acid reaction is formed in the soil profile. Such soils are called atoll melano-humus-carbonate soils.

Rice. 9.2. Coral barrier reef in French Polynesia

Rice. 9.3 Atoll in the area of ​​about. Moorea in the Pacific

Humus-carbonate soils are an important natural resource of numerous island states of the Pacific and Indian Oceans, being the main plantation for the coconut palm.

Mountainous area. Mountain soils occupy more than 20% of the entire land surface. In mountainous countries, the same combination of soil formation factors is repeated in the main features as on the plains, therefore many soils of the type of automorphic soils of plain territories: podzolic, chernozems, etc. are widespread in the mountains. However, the formation of soils in mountainous and soils formed in flat and mountainous areas are clearly different. Allocate mountain-podzolic, mountain chernozems, etc. In addition, in mountainous areas such conditions are formed in which specific mountain soils are formed that have no analogues on the plains (for example, mountain-meadow soils).

Rice. 9.4. Akhyr mountains near the city of Kahramanmaras in the south of central Turkey.

One of the distinctive features of the structure of mountain soils is the low thickness of the genetic horizons and the entire soil profile. The thickness of the profile of a mountain soil can be 10 or more times less than the thickness of the profile of a similar flat soil, while maintaining the structure of the profile of a flat soil and its features.

Soil is a complex biological complex that includes mineral (mechanical) and organic parts, soil air, water, microflora and microfauna. From this complex and a combination of influencing factors, such as climatic conditions, planting dates, variety, timeliness and literacy of agrotechnical techniques, the quality of growing garden crops on your personal plot depends. Also no less important when laying a garden, lawn or setting up a vegetable garden is the type of soil... It is determined by the content of mineral and organic particles.

The choice of crops, their placement, and ultimately the harvest depends on what type of soil prevails on your site. Depending on this, a specific complex is developed to maintain fertility through proper processing and the introduction of the necessary fertilizers.

The main types of soils that owners of backyards and summer cottages most often encounter are: clay, sandy, sandy loam, loamy, calcareous and marshy. A more accurate classification is as follows:

• Organic composition- chernozems, gray soils, brown and red soils.

Each soil has both positive and negative properties, which means it differs in recommendations for improving and selecting crops. In their pure form, they are rare, mainly in combination, but with a predominance of certain characteristics. Let's consider each type in detail.

Sandy soil (sandstones)

Sandstones are light soil types. They are friable, free-flowing, water easily permeable. If you pick up a handful of such earth and try to form a lump, then it will crumble.

The dignity of such soils- they warm up quickly, aerate well, and are easy to process. But at the same time, they quickly cool, dry out, weakly retain mineral substances in the root zone - and this flaw... Nutrients are washed out by water into the deep layers of the soil, which leads to a decrease in the availability of useful microflora and suitability for growing crops.

Sandstone

To increase the fertility of sandstones, it is necessary to constantly take care of improving their compacting and binding properties. This can be achieved by introducing peat, compost, humus, clay or drill meal (up to two buckets per 1 m²), using green manure (embedded in the soil), and high-quality mulching.

A more non-standard method of improving these soils is the creation of an artificial fertile layer by clay. To do this, on the site of the beds, it is necessary to arrange a clay castle (lay out the clay with a layer of 5 - 6 cm) and pour 30 - 35 cm of sandy loam or loamy soil on it.

At the initial stage of processing, it is allowed to grow the following crops: carrots, onions, melons, strawberries, currants, fruit trees. Cabbage, peas, potatoes and beets will feel a little worse on sandstones. But, if you fertilize them with fast-acting fertilizers, in small doses and often enough, then you can achieve good results.

Sandy loam soil (sandy loam)

Sandy loam is another option for light soils in terms of texture. They are similar in quality to sandstone, but contain a slightly higher percentage of clay inclusions.

The main advantages of sandy loam- they have a better holding ability to mineral and organic substances, they quickly warm up and hold it for a relatively long time, they pass moisture less and dry out more slowly, they are well aerated and easy to process.

Sandy loam soil

With conventional methods and the choice of zoned varieties, anything can grow on sandy loam soil. This is one of the good options for gardens and vegetable gardens. However, the methods of increasing and maintaining fertility for these soils are also acceptable. This involves the introduction of organic matter (in normal doses), sowing green manure crops, and mulching.

Clay soil (alumina)

Alumina refers to heavy soils with a predominance of clay and loess (silty) sedimentary rocks. They are difficult to cultivate, have little air and are colder than sandy soils. The development of plants on them is somewhat delayed. On the surface of very heavy soils, water can stagnate due to the low coefficient of water absorption. Therefore, it is quite problematic to grow crops on it. However, if the clay soil is properly cultivated, it can become fertile enough.

How to identify clay soil? After digging, it has a coarse, lumpy dense structure, moisturized sticks to the legs, poorly absorbs water, and easily sticks together. If you roll a long "sausage" out of a handful of wet alumina, then it can be easily bent into a ring, while it will not crumble or crack.

Clay soil

To facilitate the processing and enrichment of alumina, it is recommended to periodically apply substances such as coarse sand, peat, ash and lime. And you can improve biological qualities with the help of manure and compost.

The introduction of sand into the clay soil (no more than 40 kg per 1 m 2) allows to reduce the moisture capacity and thus increase its thermal conductivity. After sanding, it becomes suitable for processing. In addition, its ability to heat and water permeability increases. Ash enriches with nutrients. Peat loosens and increases water absorption properties. Lime reduces acidity and improves soil air conditions.

Recommended trees for clay soils: hornbeam, pear, pedunculate oak, willow, maple, alder, poplar. Shrubs: barberry, periwinkle, hawthorn, weigela, dogwood, viburnum, cotoneaster, hazel, mahonia, currant, snowberry, spirea, henomeles or Japanese quince, mock-orange or garden jasmine. From vegetables potatoes, beets, peas and Jerusalem artichoke feel good on clay.

On clay soils, special attention should be paid to loosening and mulching.

Loamy soil (loamy soil)

Loamy soil is the most suitable type for growing horticultural crops. It is easy to process, contains a large percentage of nutrients, has high air and water permeability, is able not only to retain moisture, but also to distribute it evenly over the thickness of the horizon, and retains heat well.

You can determine the loam by taking a handful of this soil in the palm of your hand and rolling it up. As a result, you can easily form a sausage, but when deformed, it collapses.

Due to the totality of the available properties, the loamy soil does not need to be improved, but it is only necessary to maintain its fertility: mulch, periodically apply organic and mineral fertilizers.

All types of crops can be grown on loams.

Lime soil

Calcareous soil is classified as poor soil. Usually it has a light brown color, a large number of stony inclusions, does not give iron and manganese to plants well, and can have a heavy or light composition. At elevated temperatures, it quickly heats up and dries out. In crops grown on such soil, foliage turns yellow and growth is unsatisfactory.

Lime soil

To improve the structure and increase the fertility of calcareous soils, it is necessary to regularly apply organic fertilizers, mulch, sow green manures, and apply potash fertilizers.

Everything can be grown on this type of soil, but with frequent loosening of row spacings, timely watering and the thoughtful use of mineral and organic fertilizers. Weak acidity will suffer: potatoes, tomatoes, sorrel, carrots, pumpkin, radish, cucumbers and salads. Therefore, they need to be fed with fertilizers that tend to acidify (ammonium sulfate, urea), and not alkalize the soil, for example.

Swampy soil (peat bog)

Swampy (peat) soils are not uncommon in garden plots. Unfortunately, it is difficult to call them good for growing crops. This is due to the minimum content of plant nutrients in them. Such soils quickly absorb water, give it up just as quickly, warm up poorly, and often have a high acidity index.

The only advantage of swampy soils is that they retain mineral fertilizers well and are easy to cultivate.

Swampy soil

To improve the fertility of swampy soils, it is necessary to enrich the land with sand or clay flour. Liming and fertilization can also be applied.

For laying a garden on peat soils, it is better to plant trees either in pits, with soil individually laid for culture, or in bulk hills, with a height of 0.5 to 1 meter.

Using as a vegetable garden, the peat bog must be carefully cultivated or, as in the version with sandy soils, a clay layer should be laid and loam mixed with peat, organic fertilizers and lime should be poured onto it. To grow gooseberries, currants, black chokeberries and garden strawberries, you can do nothing, just water and weed out the weeds, since these crops grow on such soils without domestication.

Chernozems

Chernozems are soils of high potential fertility. Stable granular-lumpy structure, high humus content, high percentage of calcium, good water-absorbing and water-retaining capacity allow us to recommend them as the best option for growing crops. However, like any other soil, they tend to deplete from constant use. Therefore, already 2 - 3 years after their development, it is recommended to apply organic fertilizers to the beds, sow green manures.

Chernozem

Chernozems can hardly be called light soils, so they are often loosened by adding sand or peat. They can also be acidic, neutral and alkaline, which must also be controlled. To define black soil, you need to take a guest of the earth and squeeze it in the palm of your hand. This should leave a black, bold print.

Serozem

For the formation of gray soils, loess-like loams and loess with pebble bedding are required. Plain serozem is formed on clayey and heavy loamy deluvial and alluvial rocks.

The vegetation cover of zones with gray soils is characterized by a pronounced zonation. At the lower level, as a rule, there is a semi-desert with bluegrass and sedge. It gradually passes into the next belt with semi-desert and representing it bluegrass, sedge, poppy and barley. The higher regions of the foothills and low mountains are mainly occupied by wheatgrass, barley and other crops. In the areas of river floodplains, willows and poplars grow.

Serozem

The following horizons are distinguished in the profile of gray soils:

• Humus (from 12 to 17 cm thick).
• Transitional (15 to 26 cm thick).
• Illuvial carbonate (60 to 100 cm thick).
• Dusty-loamy with inclusions at a depth of more than 1.5 m. Fine-crystalline gypsum.

For sierozem soils are characterized by a relatively low content of humic substances - from 1 to 4%. In addition, they are characterized by an increased level of carbonates. These are alkaline soils with negligible absorption rates. They contain a certain amount of gypsum and readily soluble salts. One of the properties of serozem is the biological accumulation of potassium and phosphorus. Soils of this type contain a lot of easily hydrolyzable nitrogen compounds.

In agriculture, sierozem soils can be used subject to special irrigation measures. Most often, cotton is grown on them. In addition, beets, rice, wheat, corn and melons can be successfully cultivated in areas with gray soils.

To improve the quality of gray earth soils, in addition to irrigation, measures are recommended to prevent secondary salinization. It will also require regular application of organic and mineral fertilizers, the formation of a deep arable layer, the use of the method of alfalfa-cotton crop rotation and sowing of green manure.

Brown soils

Brown forest soils are formed on variegated and red-colored rubble-loamy, proluvial, alluvial and alluvial-deluvial rocks of the plains, located in the foothills under deciduous, beech-hornbeam, oak-ash, beech-oak and oak forests. In the eastern part of Russia, they are localized on the foothill and intermontane plains and are located on clay, loamy, alluvial and eluvial-deluvial bases. Mixed, spruce, cedar, fir, maple and oak forests often grow on them.

Brown soils

The process of formation of brown forest soils is accompanied by the emergence of products of soil formation and weathering from the soil profile. They usually have a mineral, organic and organo-mineral structure. For the formation of this type of soil, the so-called litter (fallen parts of plants), which is a source of ash components, is of particular importance.

The following horizons can be identified:

• Forest litter (0.5 to 5 cm thick).
• Coarse humus humus.
• Humus (up to 20 cm thick).
• Transitional (25 to 50 cm thick).
• Maternal.

The main characteristics and composition of brown forest soils vary significantly from one horizon to another. In general, these are soils saturated with humus, the content of which reaches 16%. Fulvic acids occupy a significant part of its constituents. Soils of the presented type are acidic or slightly acidic. Claying processes often take place in them. Sometimes the upper horizons are depleted in silty components.

In agriculture, brown forest soils are traditionally used for growing vegetables, grain, fruit and industrial crops.

To determine what type of soil prevails on your site, it is best to contact a specialist. You will be helped to find out not only the type of soil by the content of minerals, but also the presence of phosphorus, potassium, magnesium and other useful microelements in it.

Lesson objectives:

1. Coordinate the independent work of students, taking into account their personal characteristics, in order to create the most favorable conditions for their manifestation.
2. Think over the main types of communication, forms of cooperation between students and the teacher, taking into account personal interaction, equal partnership in the lesson.
3. In the conditions of student-centered learning, to provide each student, based on his abilities, inclinations, interests, subjective experience, the opportunity to realize himself in the knowledge of the diversity of Russian soils and their dependence on vegetation.

Lesson Objectives:

1. Using the subjective experience of each student about soils, the ability to independently obtain information using maps, to form knowledge about the diversity of soils in Russia.
2. Encourage students to make their own choice and use the methods of in-depth study of the material about the main types of soils in Russia that are most significant for them.
3. Stimulate the student to self-development and self-expression when choosing and completing practical tasks, solving problematic issues.
4. To provide assistance to the creative group in the study of the soils of our area, the impact of economic activities of the population on pollution and soil protection.
5. Conduct reflection, assessment of the acquired knowledge.

Learning new material.

Teacher: Guys, look at the soil map of Russia. What are the main soils moving from north to south.

Teacher: What are the main natural components involved in the formation of soils:

1. Rocks
2. Plants and Animals
3. Climatic conditions
4. Relief
5. Ground water level
6. Permafrost
7. Time

Teacher: Do you think the distribution of soils not only in Russia, but throughout the world is chaotic or obeys the laws of nature?
Students: The distribution of soils obeys the law of latitudinal zoning, in the mountains of altitudinal zonality.
Teacher: Now we will familiarize ourselves with the main types of soils in Russia and try to fill out a table characterizing soils.

The main soils of Russia

Arctic soils:

1. Low temperatures throughout the year.
2. The parent rock is covered with snow or ice.
3. The vegetation cover is represented by mosses and lichens.
4. The soil formation process is difficult.
5. Arctic soils are formed on insignificant areas of the Arctic islands, not occupied by snow and ice, in the short summer.

Tundra-gley soils:

1. Summer is cold and short.
2. Permafrost.
3. Vegetation cover: mosses, lichens, undersized shrubs.
4. Soil formation slowed down due to lack of heat.
5. Humus contains 1.5%
6. Natural area - tundra.

Podzolic soils:

Summer is cool, K uvl. > 1.

1. Excessive humidification leads to washing of humus, an infertile leaching layer - podzol - is formed.
2. The vegetation cover is represented by needles.
3. Soil formation is difficult, since the needles contain resins that impede rotting and give increased acidity.
4. Humus - 1.5 - 2%.
5. The natural area is taiga.

Sod-podzolic soils:

Summer is warm, To uvl. > 1.

1. Soil leaching only in spring.
2. The vegetation cover is more varied.
3. The soils are more fertile.
4. Humus - 2%.
5. Natural area - mixed forests.

Gray forest soils:

1. The climate is temperate continental with warm summers. = 1.
2. The vegetation cover is represented by the remains of forest and herbaceous vegetation.
3. The soils are fertile.
4. Humus 2 - 5%.
5. Natural area - deciduous forests.

Chernozem soils:

1. Moderate continental and continental warm climate, K uvl. =< 1; 0,9.
2. The vegetation cover is represented by herbaceous vegetation, there is no leaching, which contributes to the accumulation of humus.
3. The soils are very fertile.
4. Humus - 10 - 12%.
5. The natural zone is the steppe.

Chestnut soils:

1. Continental arid climate, a lot of heat, K uvl.< 1; 0,8.
2. The vegetation cover is represented by herbaceous vegetation, but a lot of heat and little moisture forms a less diverse vegetation cover.
3. The soils are fertile.
4. Humus 3 - 5%.
5. The natural zone is dry steppes.

Brown and gray-brown soils:

1. Sharp continental, dry climate, K uvl.< 0,5.
2. Small vegetation cover.
3. Soil formation is hindered by high temperatures, decreased moisture, and plant litter.
4. Humus - 1%.
5. The soils are saline.
6. Natural area - deserts.

Teacher: You and I have traced the change of soils from north to south on the territory of the Russian Plain. What conclusions can you draw about soil diversity and the main natural components that influence soil formation?

Pupils: There is a latitudinal zoning. As a result of changes in the climatic characteristics of heat and moisture, the vegetation cover changes, and the formation of various soils directly proceeds from the plant litter. Equally bad for the formation of soils is the lack of heat and moisture, as well as their excess. Fertile soils are formed with a sufficient amount of heat and moisture and annual plant litter.

Teacher: What soil is typical for our area?

Pupils: Chernozems.

Teacher: Soils are one of the main treasures of the Belgorod region. The main property of the soil is the presence of humus in it. The region is located in favorable natural and climatic conditions, which contributed to the formation of highly fertile soils. Students of the research group will tell about the soils of our village.

Pupils: The territory of the village of Pushkarnoye is located northwest of the city of Belgorod in the basin of the small rivers Vezelka and Iskrinka, tributaries of the Northern Donets in a pronounced forest-steppe zone. Our steppe spaces are combined with forest tracts, where vegetation of deciduous forests grows.

In forest areas, the soils are gray and dark gray forest soils. On the flat steppe regions - ordinary chernozems. In the river valleys there are chernozem-meadow and floodplain soils.

The acidity of soils in the northwestern part of the Pushkar fields is increased, liming is required.

The duration of the agricultural development of the territory affects the fertility and humus reserves in soils. Man, through his activities, negatively affects the soil. On the territory of our village, the relief is very difficult, there are few flat places, so plowing should be carried out across the slopes, there are many ravines, which also complicates the work in the fields. Water erosion prevails, and the washout of the humus layer from the fields. The ecological detachment of our class is fighting spontaneous dumps in the territory of the village. The floodplain part of the Vezelka River, as well as the river itself, from household waste, was taken under our protection. People in their gardens continue to burn fires, plant remains in spring and autumn, not realizing that this is a valuable raw material that increases soil fertility and fires burn microorganisms present in the soil.

Teacher: Soil is a complex natural formation. Recent research by scientists is increasingly confirming that the soil is a special natural formation, transitional between living and nonliving.

Thank you guys for the work done. They carried out research work and introduced us to the main soils of our village.

Now we will give the floor to N.V. Bakhaev, he will acquaint us with new technologies that allow us to obtain high yields; but take good care of the soil, since fertility is the main quality of the soil Agro-saving technologies.

The modern concept of agro-saving technologies includes the use of all ecologically reasonable and ecologically low-hazard methods of protecting cultivated plants from harmful organisms.

The main methods are agrotechnical, biological and chemical.

1. The agrotechnical method includes the following types:

a) Crop rotations. Correct crop rotation is the main part of the farming system and one of the stages of weed control, since crops affect different types of weeds in different ways.

b) Tillage is essential in weed control.

2. The biological method involves the control of weeds, crops of cultivated plants that are highly competitive in relation to weeds, that is, phytocenoses of some crops strongly suppress the development of weeds (rye, winter wheat).

Biological objects are also used - insects, microorganisms, nematodes, which suppress the growth and development of weeds. But this method has not yet received widespread development in Russia.

3. Chemical method. Currently, herbicides are actively used. It is not decisive in relation to other methods, but is used in combination with them. Due to the complex and not always uniquely beneficial effect of pesticides on ecosystems. Their use should be rational, that is, economically and environmentally sound.

All of the above agro-saving technologies, plus the introduction of mineral fertilizers, a natural factor, (weathering, washing out and so on) all the same, it has a negative effect on soil fertility, that is, the content of humus and, of course, there is a problem of restoring soil fertility, and one of the ways to save what is left is the introduction of organic fertilizers, the biological method and rationally ecologically sound agricultural methods.

Homework: Individual multilevel assignments.

Verification of the actual material.

1. Why is there a change in soil?
2. Who is the founder of the science of soil science?
3. What are the most fertile soils?

Ability to work with the map.

1. What soils are located in the Yaroslavl region?
2. What soils formed in the lower reaches of the Volga River?
3. Determine the soil on the Kola Peninsula?

Causal relationships.

1. Why is the accumulation of humus in the forest zone decreasing?
2. Why are the most fertile soils in Russia - chernozems?
3. Why do taiga soils contain little humus, but high acidity?

Creative application of knowledge.

1. Give examples proving the negative impact of humans on soil, leading to its degradation.
2. Give examples of soil protection.
3. Why use fertilizers with care?

Reflection:

1. I appreciate my work ...
2. I found out today ...
3. I was…

Soil is the thin top layer of the earth's crust that gives life to plants. This is an independent natural body, which is a cross between living and dead matter. The lithosphere, atmosphere, hydrosphere and biosphere interact in the soil, and the density of the living matter of the planet is maximum.

The most valuable property of the soil is fertility, i.e. the ability to provide plants with the necessary nutrients and moisture.

The soil consists of mineral particles, organic matter mainly of plant origin, soil water, soil air and living organisms inhabiting it. In different regions of the Earth, soil thickness ranges from a few centimeters to 2-3 meters.

Soil formation depends on a combination of soil formation factors that differ over vast areas of the Earth. For example, where it is low, there is little rainfall and vegetation is scarce, the soil layer is thin and contains little humus. But in areas with a sufficient amount of heat and precipitation, with rich herbaceous vegetation, powerful fertile soils are formed.

The Sun heats the spherical surface of the Earth unevenly: the areas above which it stands high receive the most heat. The farther from the equator, the greater the angle the rays reach the earth's surface and, therefore, less thermal energy per unit area. Above the poles, the Sun's rays only glide over the Earth. The climate depends on this: hot at the equator, harsh and cold at the poles. The main features of the distribution of flora and fauna are also related to this. According to the features of heat distribution, seven heat zones are distinguished. In each hemisphere there are zones of eternal frost (around the poles), cold, moderate. The hot belt at the equator is one for both hemispheres. Heat zones are the basis for dividing the earth's surface into geographic zones: areas that are similar in the prevailing types of landscapes - natural-territorial complexes that have a common soil, vegetation and fauna.

But the land surface of the Earth in different places receives not only different amounts of solar energy, but also has many additional dissimilar conditions - for example, remoteness from the oceans, uneven relief (mountain systems or plains) and, finally, unequal height above sea level. Each of these conditions strongly affects the natural features of the Earth.

Plants and animals, fungi and microorganisms belong to living nature, and rocks, air, surface and ground waters - to inanimate nature. All of them are integral parts of natural complexes, in a wide variety presented on Earth. A natural complex located in a limited area is called a landscape. A separate landscape can be called the top of a hill overgrown with spruce forest or a flood meadow in the river valley. Climate, relief, water, soil, plants and animals are the main components of the landscape, they interact with each other in a complex way, forming a single natural system. The upper boundary of the landscape is that part of the troposphere where dust of terrestrial origin spreads, and the lower boundary is the horizon of groundwater.

Landscapes are the building blocks of more complex natural systems, such as natural areas. Each continent has its own characteristic set, and all together the continents and oceans make up the largest and most complex natural system - a geographic shell. The word "system" is translated from Greek as "whole, consisting of parts."

At present, almost all landscapes of the planet are disturbed to one degree or another. Man has created some landscapes anew, for example, quarries for the extraction of minerals, reservoirs, cities. Nowadays, the influence of man on nature is enormous. However, it is necessary to understand that by thoughtlessly interfering with its laws, we cause colossal harm to nature, and therefore to ourselves. After all, the life and health of people are directly related to the state the environment therefore, the preservation of nature is the main condition for the very existence of mankind. Only a careful and reasonable attitude to natural resources will allow avoiding a global ecological catastrophe, preserving our planet for future generations.

Site search.

Each natural zone is defined using several features: type of vegetation, fauna, climatic conditions, etc. The type and composition of the soil also directly depends on the listed factors. In addition, moisture, volatility, and relief features affect the fertility of the land.

Soil gives life to plants, which are the beginning of ecosystem food webs. Therefore, this or that type of natural complex and climate plays a decisive role in the formation of the soil cover.

Relationship between soil and natural zones

This table proposes to consider the correspondence between ecosystem types and main soil classes.

The variety of surrounding landscapes and climates affects the fertility of the land in different ways. So, some soils can give life to a huge number of crops, while others are practically barren.

Soil types

Soil, like vegetation, is formed under certain climatic conditions. Therefore, the tundra is overgrown with mosses and low shrubs, and, for example, the tropical forest is distinguished by lush and lush vegetation. All soil types are arranged according to geographic zonation.

Tundra

The tundra zone, which occupies about 3%, is located in the conditions of the subarctic climatic zone. The ecosystem covers the entire coast of the Arctic Ocean and the islands north of Antarctica. The land in the tundra is formed under the influence of severe frosts, excessive moisture and modest vegetation cover.

Depending on the relief and drainage, they distinguish the following types tundra soils:

• sour brown - receive a sufficient amount of moisture and oxygen, are located in the mountain tundra or on hills;
• tundra-gley - are, on the contrary, in the lowlands, are formed under conditions of stagnant water, poor drainage and lack of oxygen;
• peat-gley - located in the southern tundra and forest-tundra, where the climate is warmer and milder than in the typical tundra;
• tundra-boggy - occur in depressions of the relief, can form tundra salt marshes;
• soddy acidic - located in the floodplains of rivers, grasses and cereals grow on them, as a result of which these soils are relatively rich in nutrients;
• polygonal peat bogs - common in some areas of the tundra, formed during the Holocene, when there was a forest zone in these places.

The entire territory of the tundra is covered by a layer of permafrost. It is located close to the surface, as a result of which the land is highly moistened and swampy. Strong cooling of the soil adversely affects the processes of soil formation and vegetation development.

Podzolic

To the south of the tundra there is a huge ecosystem - the taiga. Podzolic soil type is typical for these northern coniferous forests. Its distinctive feature is high humidity and high oxidation state due to fallen coniferous needles.

Since the taiga zone has a large length from north to south, the podzolic type is subdivided into several types depending on climatic conditions:

• gley-podzolic - common in the northern taiga, shrubs, dwarf trees, northern conifers grow on them;
• actually podzolic - typical for a typical taiga, where spruce, cedar, fir, pine, etc; grow on a cover of moss and lichen;
• sod-podzolic - the southern taiga zone, where deciduous trees begin to mix with conifers.

In addition to distribution over subzones, podzolic soils are divided according to layer thickness, structure and nature of soil formation.

Gray forest

This type of soil lies beneath the surface of broadleaf forests. It contains a significant proportion of humus, which gives the soil a shade from light to dark gray.

Depending on the content of organic matter and fertility, forest soils are subdivided into:

• light gray - the humus content is insignificant (up to 5%), in their characteristics they are close to the sod-podzolic soils of the southern taiga;
• gray - the share of humus here can be up to 8%, humic acids are also present;
• dark gray - the amount of organic matter reaches 10%, this is the most fertile and slightly acidic type of forest soil.

This amount of organic matter is formed due to the relatively dry climate, as well as the processes of decay of fallen leaves and grass cover.

Chernozem

Chernozem soils are formed in steppe and forest-steppe regions with a warm, dry climate and rich meadow-herbaceous vegetation. This is the richest type of soil cover in organic and mineral substances. Chernozem is rich in magnesium, iron and calcium, and the humus content reaches 15%, the layer thickness of which is 1-1.5 m.

By composition, chernozem is divided into subtypes:

• podzolized - painted in gray or dark gray, and due to podzolization processes have a characteristic whitish bloom;
• leached - unlike the podzolized subtype, they have no plaque, but contain a leached brownish horizon;
• ordinary - located in the north of the steppe zone, have a dark gray or black color, the thickness of the humus layer reaches 80 cm;
• typical - in them the chernozem processes are expressed as much as possible, the thickness of humus can occupy more than 120 cm;
• southern ones are widespread in the south of the steppes, there is a gradual decrease in the proportion of humus (up to 7%), and the thickness of the fertile layer is about 60 cm.

At present, the areas occupied by chernozem soils are almost entirely plowed up. Only small areas in ravines, gullies, virgin fields, and also in reserves remained untouched.

Swamp

The main area of ​​distribution is the plains covered with tundra and taiga. Swampy areas are formed as a result of excessive moisture, as well as processes such as gleying and peat formation. The term "gleying" means that the soil is formed with the participation of microorganisms and the constant washing of a significant layer of soil. Peat is created as a result of decomposition of plant residues.

Depending on the location on the surface of the relief, the composition of vegetation and soil, swamps are divided:

• riding - occupy flat flat areas, are formed as a result of the influence of underground or atmospheric waters, the surface is covered with sphagnum mosses;
• transitional - occupy an intermediate position between the upland and lowland type, the formation occurs with alternating moistening with hard and soft waters;
• low-lying - located in the depressions of the relief, sedge and cereal grasses, dwarf birches, willows, etc. grow on them.

Peat of lowland bogs has the most advantageous properties: it is characterized by a low degree of acidity and is saturated with minerals. Swamp soils form best in small bodies of water and lakes with stagnant water.

Meadow

Meadow soils are formed in places where meadow vegetation grows.

This soil type is divided into two subtypes:

• typical meadow - formed in the area of ​​occurrence of groundwater by 1.5-2.5 m, under the plants of meadow zones;
• wet meadow (swampy meadow) - are located in low areas of river valleys, in conditions of constant moisture, cereal and sedge grasses grow on them.

All types of meadow soil have a good humus content (4-6%), therefore they are intensively used for agriculture.

comparison table

It contains a brief description of the natural complexes, as well as their geographic location, soil and vegetation that grows there.

It can be concluded that the most favorable conditions for the development of flora are a warm climate and high, year-round humidity.

Economic value

Soil is an essential element in the formation of all living organisms on Earth. In this case, the composition of the soil is formed due to the life processes of plants and animals. But not every type of soil can give a good harvest.

What type of soil is best for growing certain crops is written below:

1. Clay. With the addition of peat, sand and ash, it is great for growing fruit trees, shrubs, potatoes, peas, beets.
2. Sandy. It is fertilized with peat, compost, clay, or mulching. This type of soil is suitable for growing almost all crops.
3. Sandy loam. To increase fertility, fertilizers are applied, mulch, and also plant green manure plants. It can also grow almost all types of vegetables and fruits.
4. Loamy. It contains a large amount of nutrients, you just need to add mineral fertilizers and mulch. Suitable for most types of crops.
5. Chernozem. The most fertile type of soil that does not require fertilization at first. After a few years, it is recommended to sow green manure plants and add organic matter. All fruit and vegetable crops take root on it.
6. Peat boggy. It is recommended to apply fertilizers from sand, clay, phosphorus and organic matter into it. It is good to grow berry bushes on such soil.
7. Limestone. Requires a lot of fertilizers due to lack of manganese and iron. Suitable for plants that are not too demanding on the acidity of the soil.

Soil is a unique natural phenomenon. When drawing up a plan for the cultivation of a plot or field, it is necessary to correctly calculate the load on the soil, because the formation of a small layer of earth takes several thousand years.

Features of soils and vegetation of different natural zones

Each natural zone is characterized by a certain set of flora, fauna, climatic features and type of soil.

1. Arctic deserts. Located in the north of Eurasia and North America. Vegetation is practically absent, the soil is infertile.
2. Tundra. Covers the coast of the Arctic Ocean. The land is covered with mosses, lichens, grasses. In the south of the zone, shrubs and dwarf trees begin to appear. The soil is thin, there is permafrost.
3. Taiga. The largest ecosystem by area. Occupies most of the temperate forests. Coniferous trees dominate: pines, spruces, firs, larch, cedars. The soil is acidic, cold and of little use for most plants.
4. Mixed forests. They are located south of the taiga. Deciduous and coniferous trees. The land is more fertile due to more plant residues.
5. Broadleaved forests. They are located in Europe, the Russian Plain, Asia, and in some places in South America. Oaks, ash trees, lindens, maples grow here. The soil is fertile thanks to fallen leaves and a warm climate.
6. Steppe and forest-steppe. The Russian steppes occupy a wide strip in the south of the country. On other continents, in climatic and natural conditions, African savannas, North American prairies and South American pampas are similar to the steppes. Grassy plains mixed with small forests in the north. The most fertile soil, consisting of varieties of chernozem.
7. Semi-deserts and deserts. They are located in the south of Eurasia, in Africa, in Australia. Occasionally there are plants - shrubs, cacti, cereals and herbs. The land is saline, the hot and dry climate prevents most of the plants from growing.
8. Subtropics and tropics. Located on the Mediterranean coast. The earth is colored red-yellow due to the large amount of iron. The subtropics are heterogeneous: acacias, chestnuts, oaks, hornbeams, and beeches grow in the subtropical forests in southern Russia. In other areas of the zone, pines, oaks, ferns, bamboos and palms coexist at the same time. A huge number of thermophilic plants grow in tropical forests.

Thus, vegetation and soil composition are interconnected: the more plants, the warmer the climate, the richer and more saturated the land will be.

Animals

Natural areas are inhabited by a wide variety of animals that have been able to adapt to the conditions of these places. Consider the composition of the fauna of various ecosystems.

Arctic

The coldest zone is inhabited by animals and birds that are perfectly adapted to extreme frosts: very thick fur or feathers, white color to hide in snowy spaces, etc. The total number of inhabitants is small, but they all have their own uniqueness and beauty: polar bears, arctic foxes, arctic hares, snowy owls, walruses, seals.

Tundra

There is already a greater variety of living organisms. Many animals move to the south for the winter, to the forests, but there are also those who live in the tundra all year round. The main inhabitants of the tundra are represented by reindeer, arctic foxes, hares, wolves, white and brown bears, lemmings, and polar owls. There are a lot of mosquitoes and midges in the tundra due to the large accumulation of swamps.

Forest zone

Forests of a temperate climate stretch in a wide strip from the northern forest-tundra to the southern forest-steppe. The diversity of fauna also varies from north to south. So, in the taiga, the species composition of animals is not as diverse as in mixed and deciduous forests. But in general, the animal composition of the forest zone is approximately the same: brown bears, wolves, foxes, lynxes, elks, red deer, and hares.

Steppe

Large animals have nowhere to hide in the wide and open spaces of the steppes, so small predators and animals live here. These are mainly steppe wolves, corsac foxes, saigas, hares, marmots, prairie dogs, bustards, storks.

Desert

If the Arctic is an extremely cold desert, then the tropical type of this zone is very hot and dry. The local inhabitants have learned to do without water for a long time and have adapted to the unbearable heat: camels, antelopes, fennec foxes, monitor lizards, scorpions, snakes and lizards.

Tropics

The rainforests are home to the largest variety of animals on the planet. These forests are multi-tiered, and each tier is inhabited by thousands of different creatures. Among the main inhabitants are: leopards, tigers, elephants, antelopes, okapis, gorillas, chimpanzees, parrots, toucans, as well as a huge number of butterflies and insects.

The richest belt in vegetation

The regions with the most diverse and abundant flora and fauna are the equatorial and subequatorial climatic zones of the Earth. On ferralite red-yellow soils, multi-tiered tropical forests grow and develop. Tall trunks of palms, ficuses, chocolate, banana, iron and coffee trees are entwined with vines, mosses, ferns and orchids grow on their surface.

Such a variety of plants is due to the absence of frost: the temperature, even on the coldest days, does not drop below + 20 ° C. Also, the nature of the tropics is characterized by a huge amount of rainfall. During the year in the tropics, up to 7000 mm of precipitation falls in the form of heavy downpours. In conditions of constant humidity and heat, most of the plants on Earth grow and develop.

Video

This video describes the soil and plants of various natural areas.