field in Russia (10 letters). The river, in the upper reaches of which the most powerful hydroelectric power station in Russia is located (6 letters). A city famous for its arms factories and the production of gingerbread (4 letters). The city in which the Trans-Siberian Railway begins, a large center of ferrous metallurgy (9 letters). One of the most important gas trunklines (6 letters).
What climatic zones and regions are located on the territory of Russia? how the amount of heat and moisture changes from north to south and from west to east alongterritory of Russia? Give a written answer.
1. Give an assessment of the main types of soils in our country. Indicate which of them are most favorable for agriculture, onwhich forests are mainly located.
2
... What types of human activities lead to a violation of the natural fertility of the soil? How can the soil be improved?
3
... What types of soil are common in your area, how are they used by humans, what activities are carried out to improve the soil?
organic matter;
B) the soil includes organic and mineral substances;
C) soil is transformed fragments of rocks and minerals;
D) the soil does not contain air.
A) mechanical composition;
B) fertility;
B) humidity;
D) the presence of soil horizons.
3. Arrange the soils as clay particles decrease in them:
A) sandy loam;
B) clayey;
C) loamy;
D) sandy.
4. The structure of soils depends on:
A) the amount of chemical elements;
B) the amount of sand particles;
B) humidity;
D) the size of its constituent particles.
5. What factor of soil formation is not natural:
A) parent breed;
B) climate;
B) relief;
D) human activity.
6. The largest amount of organic residues contains:
A) humus horizon;
B) the wash-in horizon;
C) washout horizon;
D) parent breed.
7. What type of soil is missing in Russia:
A) tundra - gley;
B) brown semi-desert;
C) chestnut;
D) yellow seeds.
8. What type of soil is the most common in Russia:
A) podzolic;
B) tundra - gley;
C) chernozems;
D) gray forest.
9. For what type of soil the predominant type of reclamation is irrigation:
A) tundra - gley;
B) chestnut;
B) podzolic;
D) permafrost - taiga.
10. What soil-forming factors determine the amount of humus in the soil:
A) relief and parent breed;
B) climate and type of vegetation;
C) the type of vegetation and the species composition of animals;
D) time and human activity.
11. The most fertile soils - chernozems - are formed within the territories. Which are common:
A) tundra vegetation;
B) forest vegetation with a predominance of conifers;
C) forest vegetation with a predominance of deciduous species;
D) steppe vegetation.
12. The anthropogenic cause of soil erosion is:
A) wind activity;
B) the activity of flowing waters;
C) destruction of woody vegetation;
D) the action of gravity.
The names of soil types come from the names of the climatic zones in which they were formed. In the taiga-forest zone, there are podzolic and sod-podzolic; in the forest-steppe and steppe - gray forest, chernozems, chestnut; in the subtropical - red soils and yellow soils.
Many soils got their name from the color of their humus horizon: black soil, gray forest, brown forest, podzol.
The soil contains a large amount of iron compounds on the surface of particles of clay, sand, and silt. It is because of the films of iron on the soil particles that it acquires its specific color. The presence of iron hydroxides gives soils various shades of reddish brown or yellowish brown. The soil acquires a black color depending on the presence of humic acid in it.
- Black color - more than 7%
- Dark gray - 5 ... 7%
- Gray - 3 ... 5%
- Light gray - less than 3%
Podzolicsoil -common in the taiga zone. Where coniferous forests grow. The upper layer is forest litter, formed from fallen needles and branches. Below is a whitish layer that does not have a pronounced structure. Below it is a brown horizon, dense, with a high clay content, the structure is expressed in the form of large lumps.
As a result of the decomposition of needles, acids are formed, which, under conditions of excessive moisture, contribute to the disintegration of mineral and organic soil particles. Abundant precipitation, in turn, wash out such soil and carry out substances dissolved by acid from the upper humus layer to the lower horizons. As a result, the upper part of the soil acquires a whitish ash color.
These soils are very acidic and therefore always need liming and a full range of fertilizers. In podzolic soil there is only 1 to 4% humus.
In Russia, podzolic soils are common in Siberia and the Far East. Trees grow on such soils much better than agricultural crops.
Only at the base of the slopes, in humid places, podzolic soils are considered the most suitable for vegetable growing. The soils of these places have a bluish color and a steel sheen on the cut. However, they tend to be too wet and need to be drained.
Sod-podzolic soils Is a subtype of podzolic soils. They form under small-leaved forests mixed with conifers. In composition, they are in many ways similar to podzolic soils. Under the forest litter there is a humus horizon, no more than 15 ... 20 centimeters deep, which has a dark brown color, followed by a sterile whitish layer.
A characteristic feature of these soils is that they are washed out by water more slowly than podzolic soils, therefore they are more fertile, but they also need liming and fertilization and can be used for growing vegetables only after improvement.
To do this, gradually, no more than 3 ... 5 centimeters annually, they deepen the arable layer and apply a large amount of organic, mineral fertilizers and lime. Spring processing of soddy podzolic soil should be carried out to a shallower depth than autumn, so as not to turn the podzol to the surface.
Gray forest soils are formed in deciduous forests. An indispensable condition for the formation of such soils is the presence of a continental climate, herbaceous vegetation and the presence of a sufficient amount of calcium (Ca). Thanks to this element, water is not able to destroy the soil structure by taking out nutrients.
These soils are colored shades of gray. The humus content in gray forest soils ranges from 2 to 8 percent. The fertility of these soils is considered average.
Gray forest soils contain slightly more humus than podzolic soils. Despite a certain amount of calcium (Ca) reserves, they still have an acidic soil environment, and therefore need liming.
Brown forest soils are common in mixed coniferous and broad-leaved forests. These soils are formed only in temperate warm climates. The color of the soil is brown. The top layer, about 5 centimeters thick, consists of fallen leaves. Beneath it is a fertile layer up to 30 centimeters thick. Even lower is a layer of clay 15 ... 40 centimeters.
Brown soils are subdivided into several subtypes with a palette of brown shades, the formation of which occurs under the influence of ambient temperature.
Chestnut soils are common in steppes and semi-deserts. This soil has a chestnut, light chestnut and dark chestnut color. Accordingly, there are three subtypes of chestnut soil, differing in color.
On light chestnut soils, farming is possible only with abundant watering. On dark chestnut soils, cereals and sunflowers grow well without watering.
The chemical composition of the chestnut soil is varied. The soil contains magnesium (Mg) and calcium (Ca), which indicates a favorable acidity (pH) level for most plants.
Chestnut soil tends to recover quickly. Its thickness is supported by the annually falling grass. You can get good yields on it, provided there is sufficient moisture. Since the steppes are usually arid.
Chestnut soils in Russia are widespread in the Caucasus, the Volga region and Central Siberia.
Sod soils are distributed mainly in Belarus, the Baltic states, in the middle and northern
zones of Russia. They contain a lot of humus, and therefore are structural and fertile. According to the reaction of the soil environment, soddy soils are slightly acidic or neutral.
Chernozems are recognized as a standard. They have an optimal granular structure, they contain a lot of humus, they have a high content of nutrients and a neutral reaction of the soil environment. When setting up a garden on black soil, fertilizer should be applied only to maintain the balance of nutrients.
Voronezh black soil stored in the Paris Chamber of Weights and Measures, being the standard of agriculture.
Peat soils are located in the wettest places, occupy about 7% of the entire territory of Russia and are located mainly in the regions of the North-West, central Russia, Western Siberia and the Far East.
They are dark, almost black in color when wet. In the thickness, you can always see incompletely decomposed plant remains. A bluish clayey horizon lies under the peat layer. Such soils are rich in organic matter, but they lack some essential macro and microelements for cultivated plants.
Due to the high moisture content, peat soils require good drainage.
Due to poor water permeability with an excess of atmospheric precipitation, they float with water.
Due to poor thermal conductivity, they slowly warm up in the spring, which is why the processing and sowing times are delayed.
They are also highly acidic and therefore need liming.
Peat soils differ into several subtypes, depending on the peat that forms them.
Low peat contains the most nitrogen, ash, lime, and therefore slightly acidic. It occurs in hollows, river valleys and depressions.
Horse peat much poorer than lowland nitrogen and ash, as it is located in higher areas. There is very little lime in it, it is sour. High moor peat is suitable for composting.
Transitional peat in terms of nitrogen, ash and lime content, it occupies an intermediate position.
Peat soils after draining them, applying the necessary phosphorus-potassium fertilizers, as well as liming, are successfully used for growing vegetables.
Floodplain soils are formed in floodplains of rivers. During the spring floods of rivers, a lot of silt settles on these soils, which makes them especially fertile. Floodplain soils have a neutral reaction of the soil environment, therefore they rarely need liming. They are rich in phosphorus, but poor in potassium.
The high part of the floodplain is dominated by sandy loam and loamy varieties of floodplain soils. In terms of structure and supply of nutrients, they are inferior to the soils of the middle part of the floodplain, but they dry out faster, which allows them to start processing them earlier. The groundwater here lies deep, and when growing vegetables, it is necessary to organize watering.
The middle part of the floodplain is represented mainly by loamy soil, which is characterized by a good granular structure and high fertility. The ground waters occur at a depth of 1.5 to 2 meters, which creates favorable conditions for the water regime for plants. The highest yields of vegetables and potatoes are obtained on these soils.
In the lower part of the floodplain, the soils are also fertile, but heavy and excessively moist, which is explained by the high occurrence of groundwater (from 0.5 to 1.0 meters) and the prolonged flood. These soils should be drained by arranging drainage ditches, after which they are suitable for growing late vegetables, especially cabbage.
Soil map of Russia and CIS countries
The main types of soils in Russia
The main types of soils in Russia
The first scientifically substantiated classification of soils in Russia was prepared by V.V.Dokuchaev in 1886. When developing it, the scientist proceeded from the conditions and nature of soil formation. Subsequently, this classification of soils in Russia was supplemented and refined by subsequent generations of Russian scientists. In the modern classification, the main types of soils are identified, the formation of which is associated with various parent rocks, terrain, climate and vegetation characteristics.
On the territory of Russia, from north to south, the following soil zones are distinguished (areas with a predominance of one main soil type): tundra, taiga-forest, forest-steppe, chernozem-steppe and a zone of dry and semi-desert steppes.
Tundra zone... It is located along the coast of the seas of the Arctic Ocean and occupies a rather vast territory of our country.
The word "tundra" in the language of the northern peoples means treelessness. A characteristic feature of the natural conditions of the tundra is the presence at a shallow depth of permafrost, which is an impenetrable waterproof layer. The soils of the tundra zone are formed under mosses, lichens and small shrubs in a harsh climate with short summers and long winters. The soils of the tundra zone are usually thin and very swampy, with a small peaty horizon on their surface, and a thin horizon with a small humus content below it.
The soils of the tundra zone are used as pastures for deer and hunting, and early vegetables, potatoes, barley, oats, and fodder crops are grown on separate drained and well-cultivated fields.
Taezhko is a forest zone. It is located on an area that makes up almost 75% of the total area of \u200b\u200bRussia. The northern border of this zone coincides with the southern border of the forest-tundra, and the southern one passes through the cities of Bryansk - Ryazan - Nizhny Novgorod - Izhevsk, then goes around the Urals from the south and continues to Tomsk, where it turns sharply to the south and, reaching the State border of Russia, continues along it to the Far East.
In the postglacial period, the formation of green vegetation in the temperate climate of the Northern Hemisphere was preceded mainly by forest species. The grasses here did not immediately succeed in taking their place. They settled in treeless places, primarily along river valleys. Where a coniferous forest appeared, the creation of humus and, in general, the natural origin of the soil proceeded very slowly. This is not the fault of the forest itself, which for a long time preserves the organic mass above the ground in the form of trunks and branches of trees, but the cool climate accompanying the formation of the forest, and the abundance of water, which, although it gives rise to all life, but at the same time washes young and unstable organic decay products of wood.
These products, in combination with mineral sedimentary rocks, almost always create an acidic environment that promotes the decomposition of organic matter, some of which leave with water into the depths of the soil. And now, after the lapse of many thousands of years, as the soil formation proceeds in our taiga-forest zone, the layer of humus does not exceed 7 ... 10 cm in natural conditions.
And immediately below it you can see a podzolic light gray layer, which has a high acidity, and then a rusty brown washout layer. Below these layers, for many meters, there are dense layers of clay or sand with rubble, that is, what is left of the Ice Age. These soils are ash-colored, which is why they are called podzolic.
When plowing, podzolic soils quickly lose their fertility, so they need organic and mineral fertilizers, as well as liming - applying lime fertilizers to the soil to eliminate soil acidity, which is harmful to many agricultural crops. After carrying out the crops of technical work to improve podzolic soils, they can get high yields of cereals, potatoes, vegetables, flax, perennial grasses, as well as use them for meadows and pastures.
In the taiga-forest zone, they are more common sod-podzolic soils that are richer in humus and less acidic than podzolic soils. Sod-podzolic soils were formed under the joint influence of podzolic and soddy soil-forming processes. However, these soils also require improvement, therefore, to increase the fertility of sod-podzolic soils, the thickness of the arable layer is increased to 20 ... 22 cm or more, organic and mineral fertilizers are constantly applied, periodically lime, and the crops of perennial and cereal grasses are expanded.
In the taiga-forest zone, there are marsh soils under which there is a peat horizon of varying thickness with a gray-gray color. Swamp soils are formed mainly as a result of land swamping. A characteristic feature of the distribution of bog soils in the taiga-forest zone is that they do not form continuous massifs, but are located in patches of different area among podzolic, soddy-podzolic and other soils.
Swamp soils are used for hayfields, but the quality of these hayfields is usually low. After draining the swamps and carrying out cultural and technical works, the bog soils turn into agricultural lands, which, with rational use, give high yields of annual and perennial grasses, fodder root crops, vegetables and industrial crops.
Forest-steppe zone... It is located south of the taiga-forest, and its southern border in the European part of Russia passes through the cities of Tula-Ulyanovsk-Ufa, in the Asian part it continues through Chelyabinsk-Omsk-Novosibirsk-Kemerovo-Irkutsk-Ulan-Ude-Chita. A characteristic feature of the territory of this zone is the winding outline of the borders and the insular location within the limits of Eastern Siberia.
Forest gray the soils of this zone were formed in a temperate warm climate, flat, undulating relief with depressions and ravines. Moreover, almost all precipitation falling in the forest-steppe zone almost completely evaporates. Gray forest soils were formed under meadow and steppe vegetation and partly under the cover of clarified broad-leaved forests. The abundance of plant residues in conditions of seasonal moisture, the saturation of forests and loess-like loams with hard bases, a weakly acidic reaction enhance the soil-forming process and contribute to the accumulation of humus and nutrients. Here loess is a non-layered porous sedimentary rock of gray-yellow or fawn color, rich in calcium carbonate.
The soils of the forest-steppe have long been developed for agricultural use, and more than 40% of them are occupied by arable land, and about 10% - by hayfields and pastures. These soils are suitable for growing winter and spring grains, potatoes, silage maize, alfalfa and other crops. But these soils must be properly processed and protected from erosion - destruction by wind and water. Agrotechnical measures to increase the fertility of these soils provide for the deepening of the arable layer, the use of all types of fertilization, liming, soil-protective crop rotations and anti-erosion treatment on the slopes.
Chernozem-steppe. This zone is located to the south of the forest-steppe zone. Within the European part of Russia, it occupies a continuous territory, and its southern border coincides with the State border of Russia and Ukraine. In the Asian part of the country, the chernozem-steppe zone reaches the Ob, and in the south it borders on Kazakhstan.
Chernozems were formed under abundant steppe vegetation in conditions of flat relief, moderately warm climate and limited precipitation. The fertility of chernozems has been created for many millennia.
Once upon a time, steppe plants such as feather grass, timothy grass, wild oats, etc. began to grow here on loesslike loams. Grasses died off every year, their remains served as food for microorganisms, insects and other animals, which contributed to their decomposition and transformation into humus. So nitrogen and phosphorus accumulated in the soil, which are necessary for plants in the first place. In humus, individual soil particles stuck together into lumps, taking the form of pea grains. A solid granular and fine-grained structure of chernozems was created.
The chernozem soils of Russia have been plowed up for more than one hundred years, and, nevertheless, they continue to be the richest soils in the world. When the necessary fertilizers are applied to such soils, the yield of agricultural crops increases significantly. These lands must be properly used and protected from wind and water erosion. In addition, it is necessary to take care of the accumulation of moisture in the soil so that in dry years the plants do not suffer from a lack of water.
Zone of dry and semi-desert steppes. This zone is located south of the chernozem-steppe zone and is located in Kalmykia and in the Astrakhan region, and within the limits of Eastern Siberia it has an insular distribution in the Minusinsk and Amur steppes.
The soils of the zone of dry and semi-desert steppes were formed under conditions of insufficient moisture and high temperatures, therefore, they contain less humus than in chernozems. Although these soils have high natural fertility, the lack of moisture, especially in dry years, does not allow obtaining sustainable yields annually. But on the other hand, with artificial irrigation on these lands, you can get high yields of agricultural crops.
For a better organization of the use of agricultural lands, soil grading is performed.
Bonitization (from Lat. Bonitas - good quality) is a comparative assessment of soils according to their most important agronomic properties, which expresses the degree of favorableness of soils for the cultivation of agricultural crops. For this, quantitative indicators are used - points that allow you to establish how much one soil is better or worse than another. The basis for appraisal is such properties or characteristics that determine soil fertility and the conditions for the development of agricultural crops. The number of these features and their specific list depend on the type of soil and the method of appraisal.
Based on the assessment of soils, soil maps are compiled, which are used for the development of soil cultivation.
Soil maps show the distribution of soil on the earth's surface, their features and properties. In terms of scale, soil maps are divided into detailed (1: 5000 and larger), large-scale (1: 10,000-1: 50,000), medium-scale (1: 100,0001: 300,000), and small-scale (1: 500,000-1: 2,000,000). Detailed soil maps are drawn up for experimental fields, variety testing plots; large-scale ones are used to organize the territory of individual farms; medium-scale and sometimes large-scale - for district, regional or republican planning.
General patterns.
The flora and fauna are biogenic components of nature, the soil (as defined by V.I. Vernadsky) is biogenic. Their difference from the previously considered components of nature is as follows:
Ø Ability to reproduce their own kind;
Ø Ability to move in space;
Ø Ability to adapt to living conditions;
Ø Ability to form communities.
For accommodation soils, rast. and belly. the world is mainly influenced by:
Climatic features (ratio of heat and moisture, degree of continentality),
The nature of the relief and
· Lithogenic base (substrate).
From here two consequences:
1. The main regularities in the placement of the considered components of nature are:
Ø latitudinal zoning;
Ø high-altitude clarity;
Ø sectorality (provinciality) (a consequence of climate change continentality).
2. These components react very quickly to changes in natural conditions (i.e. ecology!)
Animal world - the most mobile component and is most associated with vegetation.
Soils -most depend on the lithogenic base (composition of rocks).
Vegetable world- the brightest indicator of the entire complex of natural conditions, creating visual image territory and its natural conditions.
The founder of soil science is VV Dokuchaev, who called soils "derivatives of the landscape."
2.1. Conditions of soil formation. The direction, intensity of soil-forming processes and soil types are determined by climatic characteristics, namely:
ü The amount of energy resources (heat consumption for soil formation);
ü Water regime;
ü Quantity and "quality" of incoming organic matter;
ü The rate of decomposition of organic matter;
ü The number of microorganisms involved in soil formation.
As mentioned earlier, it obeys the law of zoning:
In the north, the process of soil formation is limited mainly by energy costs (little heat);
The farther south, the more heat → the amount of organic matter and microorganisms increases → the intensity of soil-forming processes and the amount of humus increase;
In the area of \u200b\u200bforest-steppe and steppes, a neutral balance of heat and moisture is observed → black soil is formed;
In the south, the soil-forming process is already limited by the amount of moisture (little) → the increase in biomass decreases → the flow of organic matter into the soil decreases → the number of microorganisms decreases → the consumption of energy resources for soil formation decreases (everything goes to evaporation) → the power of the soil profile decreases.
Zoning is most pronounced on the plains, in the south and east the zoning is somewhat obscured, and the altitudinal zonation begins to lead.
The intensity of biochemical processes is determined by thermodynamic conditions, and the directionality depends on the type of soil water regime.
2.2. Types of soil water regime:
Þ Flushing - typical for humid areas with excessive moisture. The process of leaching prevails, the removal of most chemicals from the soil. elements;
Þ Stagnant - also typical for humid areas, but confined to relief depressions;
Þ Non-flushing - only the most mobile compounds are washed out → humus is formed;
Þ Effusion - typical for arid areas - accumulation of mobile compounds occurs → soil salinization;
Þ Frozen - typical for areas with permafrost (tundra, but beyond the Yenisei and taiga).
2.3. The main types of soils. The formation of various types of soils is influenced by the following main soil-forming processes:
Ø Gleying;
Ø Podzol formation;
Ø Soddy (humus accumulation);
Ø Clay (formation of secondary clay minerals);
Ø Peat accumulation (marsh).
(These processes will be discussed in more detail in the special subject "Soil Science". You can shorten the section a little).
Let's move on to considering the distribution of soils on the territory of Russia.
On the plains from north to south :
one). Arctic soils:
· Young, poorly developed, fragmented;
· Are confined to flat parts of the Arctic coast, free of ice;
· Have a poorly differentiated shortened profile and high skeletal structure;
· The upper layers contain a lot of mobile iron, in places solonetzic;
· Gelling is atypical mainly due to the small amount of organic matter.
2) Tundra soils.Usually they are weak, the content of humus is 2-5% fulvic acids (up to 70%), high acidity and leaching from readily soluble salts and carbonates prevail in the composition. There are 4 subtypes:
Þ arctotundra humus gleyic - minimally waterlogged and gleyed, polygonal formations (permafrost) are characteristic;
Þ typical tundra-gley - a bright manifestation of the gley process, slowing down the decomposition of plant waste with the formation of coarse humus;
Þ peaty-gley and peaty-gley - are formed under conditions of difficult outflow of moisture;
Þ podzolized tundra-illuvial-humus (tundra podburs) - usually formed on sandy rocks or in conditions of rugged relief (improved drainage).
3) Forest soils.The most common type in Russia. There are 3 subtypes: podzolic, brown forest and gray forest.
Podzolic -about 30% of the territory of Russia. Formed under coniferous and mixed forests, with a moisture coefficient of 1.1-1.3 → leaching regime during a significant part of the growing season. There is a clear differentiation into horizons, a low thickness of the humus horizon (1-3 cm) or its absence, an acidic reaction of the soil solution is observed (fulvic acids prevail). Depending on the temperature, humidity conditions, the presence of permafrost and drainage, the following are distinguished:
ü gley-podzolic - (northern taiga):
ü illuvial-humus and illuvial-ferruginous (northern taiga);
ü podzolic and podzols (middle taiga);
ü sod-podzolic (southern taiga and mixed forests);
ü podzolic-boggy;
ü boggy (peat-bog and peat-gley);
ü taiga-permafrost;
ü podbury;
ü sod-carbonate;
ü sod-gley.
Brown forest soils... Distributed under deciduous and coniferous-deciduous forests of D. Vostok, the Caucasus, and the south of the Kaliningrad region. They are formed under the conditions of a leaching regime, warm and humid summers. Soil color → by high iron content. Clay (formation of secondary clay minerals) is characteristic. The profile is poorly differentiated into genetic horizons.
Gray forest soils... Typical for forest areas of the forest-steppe zone. Education is associated with broad-leaved, and in the Asian part \u003d - with small-leaved forests. The moisture coefficient is close to neutral (precipitation ~ evaporation). Therefore, the processes of removal of compounds characteristic of podzolic soils weaken and the sod process (humus formation) intensifies. From soddy-podzolic soils, gray forest soils are distinguished by a greater thickness of the humus horizon, a large amount of humus and its more uniform distribution along the profile. This type is transitional between sod-podzolic soils and chernozems.
4) Soils of forest-steppe and steppe.
Chernozems.They stretch in a continuous strip from the western borders to the foothills of Altai. To the east, they are found only in separate massifs. The sod process plays a leading role in the formation, therefore chernozems are distinguished by a high humus content. As the moisture deficit grows from north to south, 5 subtypes are distinguished. The first 3 are typical for the forest-steppe zone, the last 2 for the northern part of the steppes:
ü podzolized;
ü leached;
ü typical chernozems (max humus content - 8-12%);
ü ordinary;
ü southern chernozems.
Saline soils begin to play a significant role in the chernozem zone. malts, salt licks, less often - salt marshes.
Chestnut soils.They occupy small crops in Russia and are distributed in the southeast of the East European Plain, in the Middle and Eastern Ciscaucasia, on the Kulunda Plain and in some depressions of South Siberia. Formed in conditions of moisture deficiency and thinned grass and wormwood-cereal herbage. Therefore, they contain much less humus and have less capacity. They are divided into 3 subtypes:
ü dark chestnut;
ü chestnut;
ü light chestnut.
Brown desert-steppe soils.They have a limited distribution - mainly in the southern part of the Caspian region, where the climate aridity is even higher. They have a shortened profile, are very poor in humus (up to 2%), usually boil from the surface (i.e., contain a lot of carbonates), almost constantly show signs of solonetzicity when the gypsum horizon is shallow. Salt marshes are widespread, less often salt marshes.
Thus, the main types of soils show a well-pronounced distribution in their distribution over the territory of Russia. zoning... Quite clearly traced and sector,associated with a change in climate, vegetation, parent rocks and other factors of soil formation from west to east. Thus, in the taiga of the East European Plain, a change in the subzones of gley-podzolic and podzolic-boggy soils with podzolic and further sod-podzolic is perfectly traced. In Western Siberia, in all subzones, large areas are occupied by bog soils. In Central Siberia, taiga-permafrost soils are sharply dominant, and sod-podzolic soils are widespread only in the extreme southwest. Provinciality is well expressed in chernozem soils. Already on the East European Plain, a decrease in the thickness of the humus horizon and an increase in the humus content from the western borders of Russia to the Cis-Urals are traced, which is associated with an increase in continentality, a decrease in the depth of soil wetting and a reduction in the period of active humification. In Western Siberia, this is supplemented by the widely developed solonetsous and solodized chernozems.
Mountain soils.
In terms of their genetic properties, mountain soils correspond to soil types of plains. They differ only in that they are all thin, stony-gravelly, rich in primary, weakly weathered minerals. Only the soils of subalpine and alpine meadows have no analogues.
Mountain meadow soils are formed in a cold and humid climate of high mountains with increased solar radiation under meadows and thickets of shrubs. They are characterized by: a well-defined humus horizon, acidic reaction of the soil solution, total leaching, skeletal structure and low thickness. There are mountain meadow soils in the Caucasus, Altai and small areas in the southern Urals.
The main regularity of the change in the soil cover in the mountains is altitudinal zonality... The higher the height of the mountains, the better it is. However, latitudinal the situation affects the diversity of soils: the farther north the mountains are, the more uniform the soil cover within them, because the set of soil belts begins with the zonal type that is developed at the foot of the mountains. (Therefore, no matter how high the mountains of the Northeast are, nothing else but mountain taiga-permafrost and mountain-tundra soils can be found within them. soils of the Caucasus.
Significant differences in the soil cover are observed in mountain systems located at close latitudes, but in different parts of the country (i.e., the influence of sectors).So, in Sikhote-Alin, located at the latitude of the Caucasus, but in the area of \u200b\u200bexcessive moisture (Far Eastern monsoon), ferruginization of soils is found in all altitudinal zones: brown mountain forest, brown mountain taiga, mountain podburs taiga-permafrost.
Soil resources.
The most important property of soils is fertility (the ability of the soil to produce a crop of plants). Fertility is due to the presence of organic matter - humus (or humus). The amount of humus decreases from chernozems to the north and south:
Ø podzolic - 100 c / ha
Ø gray forest - 215 c / ha;
Ø chernozems - from 391 to 709 c / ha - optimal combination of heat and moisture and plant decay ;
Ø chestnut - from 229 to 116 kg / ha;
Ø brown desert-steppe - 62 c / ha
In Russia, all chernozems have already been plowed up. The structure of arable land in Russia:
50% - black soil
15% - gray and brown forest
15% - sod-podzolic and podzolic
· ~ 10% - chestnut.
Natural resources for expanding arable land are practically exhausted. Therefore, it is necessary to increase effective fertility through rational agricultural technology.
Completed by: Shemyakina Anastasia 8 "v" class
Soil is the top layer of the globe capable of producing crops. More than one rock is not capable of this. Soils have this property due to the presence of organic matter. The soil is composed of organic, minerals and hygroscopic moisture.
The ability of the soil to produce crops is called soil fertility. Conditions for increasing fertility: Availability of nutrients (phosphorus, potassium, nitrogen) Sufficient amount of moisture Availability of air necessary for the activity of plants Soil acidity - neutral There should be no harmful compounds (gases)
The main classification unit is considered to be the soil type (soil with the same profile structure and developing under the same conditions and under the same type of vegetation). The main types of soils in Russia include: tundra-gley, podzolic, sod-podzolic, gray forest, chernozems, brown forest, chestnut, red soils, yellow soils, serozems, bog soils, malts, salt marshes.
Tundra-gley: formed in the far north in tundra conditions, where vegetation is poorly developed, the process of gleying takes place. In these soils, a greenish-gray gley horizon is located under the upper horizon. It is formed during prolonged waterlogging and lack of oxygen in the soil.
Sod-podzolic and podzolic They occupy more than half of the country's area. They are formed under forests in the area of \u200b\u200bexcessive waterlogging (k\u003e 1). With a small amount of plant residues and intensive leaching, podzolic soils are formed in the taiga. They are poor in humus and mineral elements, therefore, infertile. In the southern part of the taiga, humus accumulates, mineral compounds are retained in the soil.
Chernozem: Chernozem soils in Russia go from the western borders to Altai and are concentrated in small areas in Transbaikalia. The chernozem zone is widespread in the steppe and forest-steppe zones. They are characterized by a black color and a high humus content, a large thickness of the A1 horizon (up to 1 m). They have a granular structure. These are the best soils of our country.
Subspecies of chernozem: Podzolized chernozem - widespread in the forest-steppe zone. There are the main features of the podzolic process (in the lower part of the A1 horizon there is a silicon-oxygen powder). Leached chernozem - associated with meadow-steppe vegetation. The main feature is that all alkaline elements occur in the C horizon. Typical chernozem is typical for the central zone. The largest amount of humus (20%). Carbonates appear in the middle of the B horizon. West Siberian chernozem is typical for the Asian part of Russia. Associated with freezing of the soil. The humus horizon is small, there is little humus.
Gray forest: Common under deciduous forests. They are characterized by the appearance of soddy, podzolic processes. The soil profile is reminiscent of a flaky pie. The humus content is different, there are 3 types of these soils: Light gray (in the northern part of broad-leaved species with a predominance of small-leaved species). Gray forest (humus content increases). Dark gray forest (formed under clear oak forests. These soils are typical for the forest-steppe).
Salt marshes: Formed in various natural zones with close groundwater. This is more often characteristic of relief depressions. In areas of poor and insufficient moisture, where the groundwater is highly mineralized, these are the most saline soils. With the close occurrence of fresh groundwater, peat-bog soils are formed.
Chestnut: These are the soils of dry steppe zones. Vegetation is poorly developed. With the onset of the summer heat, it dries up. Chestnut trees adjoin chernozem soils. Humus contains 3-4%, a significant content of ash elements. This soil is characterized by the distribution of carbonates throughout the soil profile and the occurrence of salts at different depths in the parent rocks.