Concept of erosion. Soil erosion – the process of destruction of soil cover. Soil erosion includes removal, transport and redeposition of soil mass. Depending on the destruction factor, erosion is divided into water and wind (deflation).

Water erosion– the process of destruction of soil cover under the influence of melt, rain or irrigation water.

Based on the nature of the impact on the soil, water erosion is divided into planar and linear.

Planar (surface) erosion– washout of the upper soil horizon under the influence of rain or melt water flowing down the slope. The mechanism of surface erosion is associated with the destructive impact force of raindrops and with the impact of surface runoff of rain and melt water.

Linear (gully) erosion– erosion of soils into depth by a more powerful stream of water flowing down the slope. At the first stage of linear erosion, deep streaky erosions (up to 20-5 cm) and gullies (depth from 0.3-05 to 1-1.5 m) are formed. Their further development leads to the formation of ravines. Linear erosion leads to the complete destruction of soil.

In mountainous areas, along with the development of normal forms of water erosion, mudflows(sat down). They are formed after rapid snowmelt or intense rains, moving with high speed and carry away a huge amount of material in the form of fine earth, pebbles and large stones. The fight against them requires the construction of special anti-mudflow structures.

Based on the rate of development, a distinction is made between geological (normal) and accelerated erosion.

Geological (normal) erosion- a slow process of washing away particles from the soil surface covered with natural vegetation, in which the loss of soil is compensated for during soil formation. This type of erosion occurs everywhere, causes virtually no harm and does not require soil protection.

Accelerated erosion occurs when natural vegetation is removed and soil is misused, resulting in a sharp increase in the rate of erosion. This type of erosion leads to a decrease in soil fertility, and sometimes to the complete destruction of soil cover, and requires soil protection.

Wind erosion (deflation)– the process of destruction of soil cover under the influence of wind. Depending on the size of the particles, they can be transported by the wind in suspension, jumping and sliding along the surface. There are dust (black) storms and everyday (local) deflation.

Dust storms repeat once every 3-20 years, carry away up to 15-20 cm of the surface layer of soil. In this case, large soil particles move short distances, stopping at various obstacles and in depressions of the relief. Most fine particles soil (<0,1 и <0,001 мм) в виде воздушной суспензии перемещаются на десятки, сотни и даже тысячи километров.

Everyday Deflation more slowly but regularly destroys the soil. It manifests itself in the form of top erosion and drifting snow. At crown erosion and soil particles rise high up in the vortex (turbulent) movement of air, and when drifting snow they roll over the surface of the soil with the wind or move spasmodically at a small height from the soil.

When rolling and jumping, particles hit and rub against each other, which increases their destruction. This contributes to increased deflation.

Erosion areas. Water erosion is most common in zones of gray forest soils, chernozem, chestnut soils, in agricultural areas of the taiga-forest zone, and in mountainous regions.

Wind erosion is common mainly in areas of insufficient moisture and low relative air humidity: in areas of unstable moisture, in arid areas, in deserts and semi-deserts.

Ecological consequences of erosion. As a result of erosion, a decrease in soil fertility occurs (with surface water erosion and deflation) or complete destruction of the soil cover (with linear water erosion). The decrease in fertility is associated with the gradual removal of the most fertile upper layer and the inclusion of less fertile lower horizons into the arable horizon. The degree of fertility reduction depends on the degree of washout or deflation.

As a result of erosion, the physical, chemical and biological properties of the soil deteriorate. The content and supply of humus decreases, its qualitative composition often deteriorates, the reserves of nutrients (nitrogen, phosphorus, potassium, etc.) and the content of their mobile forms decrease. The structural condition and composition deteriorate, porosity decreases and density increases, which leads to a decrease in water permeability, an increase in surface runoff, a decrease in moisture capacity and reserves of moisture available to plants. The loss of the upper most humified and structured layer leads to a decrease in the biological activity of soils: the number of microorganisms and mesofauna decreases, and the microbiological and enzymatic activity of soils decreases.

In addition, water erosion is accompanied by a number of other unfavorable phenomena: loss of melt and rainwater, a decrease in water reserves in the soil, dismemberment of fields, siltation of rivers, irrigation and drainage systems, other reservoirs, disruption of the road network, etc.

Ultimately, the deterioration of the fertility of eroded soils leads to a decrease in the yield of agricultural plants.

Conditions for the development of erosion. Distinguish natural And socio-economic conditions development of erosion. In the first case, the natural conditions themselves are predisposed to the manifestation of erosion processes. In the second case, the development of erosion is facilitated by improper human use of land. Natural conditions include climate (the number, intensity and size of raindrops; the thickness of the snow cover and the intensity of its melting), relief (steepness, length, shape and exposure of the slope), geological structure of the area (the nature of the rocks - their susceptibility to erosion, washout and deflation, the presence of dense underlying rocks), soil conditions (grain size distribution, structure, density and moisture of the upper horizon) and vegetation cover (the presence and nature of vegetation cover, the presence of turf and litter).

Concept of erosion.Soil erosion- the process of destruction of soil cover. Soil erosion includes removal, transport and redeposition of soil mass. Depending on the destruction factor, erosion is divided into water and wind (deflation).

Water erosion the process of destruction of soil cover under the influence of melt, rain or irrigation water.

Based on the nature of the impact on the soil, water erosion is divided into planar and linear.

Planar (surface) erosion- washout of the upper soil horizon under the influence of rain or melt water flowing down the slope. The mechanism of surface erosion is associated with the destructive impact force of raindrops and with the impact of surface runoff of rain and melt water.

Linear (gully) erosion- erosion of soils into depth by a more powerful stream of water flowing down the slope. At the first stage of linear erosion, deep stream erosion (up to 20-35 cm) and gullies (depth from 0.3-0.5 to 1-1.5 m) are formed. Their further development leads to the formation of ravines. Linear erosion leads to the complete destruction of soil.

In mountainous areas, along with the development of normal forms of water erosion, mudflows (mudflows). They are formed after rapid snowmelt or intense rains, move at high speed and carry away a huge amount of material in the form of fine earth, pebbles and large stones. The fight against them requires the construction of special anti-mudflow structures.

Based on the rate of development, a distinction is made between geological (normal) and accelerated erosion.

Geological (normal) erosion -- a slow process of washing away particles from the soil surface covered with natural vegetation in which the loss of soil is compensated during soil formation. This type of erosion occurs everywhere, causes virtually no harm, and does not require soil protection.

Accelerated erosion occurs when natural vegetation is removed and soil is misused, resulting in a sharp increase in the rate of erosion. This type of erosion leads to a decrease in soil fertility , and sometimes to the complete destruction of the soil cover, and requires soil protection.

Wind erosion (deflation) the process of destruction of soil cover under the influence of wind. Depending on the size of the particles, they can be transported by the wind in suspension, jumping and sliding along the surface. There are dust (black) storms and everyday (local) deflation.

Dust borax repeat once every 3-20 years, carry away up to 15-20 cm of the surface layer of soil. In this case, large soil particles move short distances, stopping at various obstacles and in depressions of the relief. The smallest soil particles (<0,1 и <0.001 мм) в виде воздушной суспензии перемещаются на десятки, согни и даже тысячи кило­метров.

Everyday Deflation more slowly but regularly destroys the soil. It manifests itself in the form of top erosion and drifting snow. At crown erosion soil particles rise high up in the vortex (turbulent) movement of air, and when drifting snow they roll over the surface of the soil with the wind or move spasmodically at a small height from the soil.

When rolling and jumping, particles hit and rub against each other, which increases their destruction. This contributes to increased deflation.

Areas where erosion occurs. Water erosion is most common in zones of gray forest soils, chernozem, chestnut, agricultural areas of the taiga-forest zone, and in mountainous areas.

Wind erosion is prevalent mainly in areas of insufficient moisture and low relative air humidity: in areas of unstable moisture, in arid areas, in deserts and semi-deserts.

Ecological consequences of erosion. IN As a result of erosion, a decrease in soil fertility occurs (with surface water erosion and deflation) or complete destruction of the soil cover (with linear water erosion). The decrease in fertility is associated with the gradual removal of the most fertile upper layer and the inclusion of less fertile lower horizons into the arable horizon. The degree of fertility reduction depends on the degree of washout. As a result of erosion, the physical, chemical and biological properties of the soil deteriorate. The content and supply of humus decreases, its qualitative composition often deteriorates, the reserves of nutrients (nitrogen, phosphorus, potassium, etc.) and the content of their mobile forms decrease. The structural condition and composition deteriorate, porosity decreases and density increases, which leads to a decrease in water permeability, an increase in surface runoff, a decrease in moisture capacity and reserves of moisture available to plants. The loss of the upper most humified and structured layer leads to a decrease in the biological activity of soils: the number of microorganisms and mesofauna decreases. microbiological and enzymatic activity of soils decreases.

In addition, water erosion is accompanied by a number of other unfavorable phenomena: loss of melt and rainwater, reduction of water reserves in the soil, dismemberment of fields, siltation of rivers, irrigation and drainage systems, other reservoirs, disruption of the road network, etc.

Ultimately, the deterioration of the fertility of eroded soils leads to a decrease in the yield of agricultural plants.

Termsdevelopment of erosion. Distinguish natural And socio-economic conditions development of erosion. In the first case, the natural conditions themselves are predisposed to the manifestation of erosion processes. In the second case, the development of erosion is facilitated by improper human use of land. Natural conditions include climate (the number, intensity and size of raindrops; the thickness of the snow cover and the intensity of its melting), relief (steepness, length, shape and exposure of the slope), the geological structure of the area (the nature of rocks, their susceptibility to erosion, washout and deflation, the presence of dense underlying rocks), soil conditions (grain size distribution, structure, density and moisture of the upper horizon) and vegetation cover (the presence and nature of vegetation cover, the presence of turf and litter).

Classificationand diagnostics of eroded soils. When diagnosing eroded soils, they take into account which soil horizons are removed during the development of water or wind erosion, due to which horizons the arable layer is formed and what its fertility is.

Below is a diagnosis of soils of varying degrees of erosion for the main types of soils.

Soddy-podzolic and light gray forest soils

Weakly washed - - plowing affected the upper part of the A 2 B horizon. The arable layer is noticeably lightened and has a brownish tint, and there is a sparse network of gullies on the soil surface; lie on gentle slopes (slope no more than 3°).

Medium washed- horizons B and B are involved in the arable land in whole or in part; the color of the arable land is brown and heavily spotted; the soil surface is eroded by a frequent network of gullies; lie on sloping slopes (with a slope of 3-5 0).

Strongly washed away -- the middle or lower part of the horizon is plowed; IK are found in separate areas on strongly sloping wavy slopes with slopes of up to 5-8°; The soil surface is brown in color and very blocky.

Gray and dark gray forest soils with a steady plowing depth of at least 20-25 cm with an initial thickness of humus horizons (A 1, A 2) of 30-40 cm.

Weakly flushed humus horizons are washed away by no more than 1/3 of the original thickness, the AoB horizon is not involved in the arable land at all or very weakly, and there are small gullies on the surface of the arable land.

Average washed - the humus layer is washed away by more than 1/3 into the arable land; the upper part of the B1 horizon is involved; the arable layer has a brownish tint.

Flushed-- the humus layer is completely washed away, the arable layer is represented mainly by horizon B and has a brown color.

Chernozem soils

A. Thick and medium-thick chernozems of all subtypes with a steady plowing depth of at least 22 cm with an initial thickness of humus horizons (A^Bj) > 50 cm.

Weakly washed -- horizon A is washed away by 30%, the arable layer does not differ in color from the unwashed soils; There are small gullies on the soil surface.

Medium washed - Horizon A is more than half washed away; the topsoil layer has a brownish tint.

Flushed - horizon A and partially horizon B are washed away; the arable layer has a brownish or brown color, is characterized by blockiness and a tendency to form a crust. B. Typical, ordinary and southern chernozems with a steady plowing depth of at least 20 cm and a thickness of humus horizons of up to 50 cm.

Weakly washed - up to 30 cm of the original thickness of humus horizons has been washed away; the small upper part of the B1 horizon is involved in the arable land,

Srednesmytyg humus horizons are washed away by 30-50%; during plowing, a significant part or the entire horizon B) is drawn into the arable layer, the latter being underlain by a transition horizon.

Washed away- most of the humus horizons have been washed away, part of the B1 horizon is being plowed up and the color of the arable land is close to the color of the rock.

Chestnutsoil

Weakly flushed- up to 30% of the original thickness of humus horizons (A-B|) has been washed away. The upper part of horizon B is involved in the arable land.

Wet-washed - 30-50% of the thickness of horizons A and B1 is washed away; when plowing, a significant part or all of horizon B1 is drawn into the arable layer.

Washed away Most of the humus layer is washed away, the horizon is plowed open, and the color of the arable land approaches the color of the soil-forming rock.

Measures to protect soils from erosion. Water and wind erosion in nature are often interrelated. This is taken into account when developing anti-erosion measures. Soil protection from erosion includes preventive measures to prevent its development and measures to eliminate erosion where it has already developed.

The set of measures aimed at protecting soils from water and wind erosion includes organizational, economic, agrotechnical, forest reclamation and hydraulic measures.

Drawing up a plan of anti-erosion measures and ensuring it implementation (rational distribution of land, soil-protective crop rotations, strip farming, regulation of livestock grazing, etc.).

Agrotechnical measures include phytomelioration techniques (crop rotations with perennial grasses, replacement of clean fallows with occupied, si deral and rocker), anti-erosion tillage (horizontal tillage, “contour” farming, slitting and mowing of soil, diking, moldless plowing with preservation of soil and crop residues), snow retention and regulation of snowmelt (forest strips and coulisses, snow plowing, digging) .

Forest reclamation measures are based on the creation of forest protective plantings (windbreaks and ravine forest strips, forest shelterbelts and shrub strips across slopes, etc.)

Hydraulic measures are used in cases where other methods are unable to prevent erosion, and are based on the creation of hydraulic structures that ensure retention or regulation of slope runoff (terracing slopes, leveling ravines with bulldozers, securing the slopes of ravines).

The system of soil protection measures should be carried out taking into account the zonal characteristics of agriculture and the natural conditions of erosion. The specific composition of anti-erosion measures is determined, first of all, by the characteristics of the territory's moisture, the duration of the growing season, relief conditions, the prevailing types of erosion and the direction of soil use.

Thus, the main negative result of erosion processes is a decrease in soil thickness, the destruction of the most fertile upper horizons and their replacement with a less fertile lower layer of soil, down to the parent rock. The soil cover, formed over centuries, in a short period of time loses its diverse ecological functions and the most important of them, productive force. The main reason for the development of erosion processes is the unsystematic use of land without agrophytocenotic protection. The main anti-erosion measures in the landscape farming system: forest reclamation, agrotechnical, hydraulic and organizational and economic.

Types of soil erosion

Soil erosion can be caused by land depletion or overgrazing. Land depletion is the result of growing the same crop on it for a number of years without replenishing the nutrient content of the soil by applying fertilizers. This leads to a decrease in soil fertility, and, consequently, in the volume of harvests. The cohesion of the soil also deteriorates, making it susceptible to erosion. Overgrazing occurs when too many livestock are grazed on one piece of land. These herds eat and trample grass and plants faster than they grow, leaving bare earth in their wake.

Thus, it is clear that soil erosion is a complex, multifaceted, and ambiguous process. In view of this, it can be classified on different grounds.

Based on the speed of development, erosion is divided into normal and accelerated. Normal always occurs in the presence of any pronounced runoff, occurs more slowly than soil formation and does not lead to noticeable changes in the level and shape of the earth's surface. Normal erosion occurs everywhere under forest and grass vegetation. It manifests itself very weakly, and the loss of soil that occurs is completely restored within a year thanks to soil-forming processes. Normal erosion is not accompanied by a decrease in fertility; observed in areas whose surface is covered with natural vegetation, unaltered by human economic activity (plowing, excessive grazing).

Accelerated is faster than soil formation, leads to soil degradation and is accompanied by a noticeable change in topography. In this case, soil loss exceeds the rate of soil formation process, resulting in a decrease in soil fertility; observed in areas with dissected and flat terrain and corresponding climatic and soil-geological conditions, where the use of land without the use of anti-erosion measures contributed to the development of destructive erosion processes. The main natural factors influencing the intensity of erosion processes are: the nature of precipitation, temperature conditions, wind activity, the presence (cover density) of vegetation, relief (steepness, length, slope exposure), soil condition (particle-size composition, water absorption capacity, structure, etc. ) . Accelerated erosion develops where natural vegetation is destroyed and the area is used without taking into account its natural features, as a result of which the process accelerates many times.

According to the causes of occurrence, natural and anthropogenic erosion are distinguished. It should be noted that anthropogenic erosion is not always accelerated, and vice versa.

Depending on the factors that determine the development of erosion, there are two main types: wind and water.

Wind erosion (deflation) of soils is the blowing, transfer and deposition of small soil particles by the wind, i.e. this is “the blowing and dispersal of soils and rocks under the influence of the wind.” Wind erosion develops on any relief elements, but it is most destructive on the plains.

The intensity of wind erosion depends on wind speed, soil stability, the presence of vegetation, relief features and other factors. Anthropogenic factors have a huge impact on its development. For example, destruction of vegetation, unregulated grazing, etc. This is the destructive effect of the wind: the blowing of sand, loess, plowed soils, the initiation of dust storms, the grinding of rocks, stones, buildings, mechanisms by carried solid particles raised by the force of the wind. According to the climatic conditions under which wind erosion occurs, there are two types:

everyday (local): “not noticeable upon superficial observation, occurs at low wind speeds annually in fields and pastures, slowly but constantly destroying soils by carrying away tiny soil particles, reduces yields, and destroys crops on wind-impacted slopes”;

dusty, or black, storms: occur during very strong and prolonged winds. Wind speed reaches 20-30 m/s or more. Dust storms are most often observed in arid areas (dry steppes, deserts). Dust storms irrevocably remove the most fertile topsoil; They are capable of dispersing up to 500 tons of soil from 1 hectare of arable land in a few hours, pollute the atmospheric air, water bodies, and negatively affect human health.

Wind erosion refers to aeolian processes, i.e. processes of destruction, transfer and deposition of soils and rocks associated with wind activity. As a result of the blowing out of the top layer of soil, eroded (deflated) soils are formed. These processes are highly developed in Canada, India, Australia, and most countries in Africa, Europe and Asia. “In the United States, according to calculations by the Soil Conservation Service, the area of ​​land affected to varying degrees by erosion is 313 million hectares, including 113 million hectares that are completely destroyed or severely damaged. More than half of the cultivated land is damaged in Canada, extremely severely eroded soils in China".

“Water erosion is the washing away and erosion of soil, and sometimes soil-forming rocks, by surface runoff of temporary water flows.” Water erosion develops only if there is a slope (the steeper and longer the slope, the greater the erosion and erosion of soil).

“There are different types of water erosion depending on the runoff of what water it is caused by: melt, rain or irrigation (irrigation erosion).” In addition, erosion can occur as a result of seasonal release of groundwater to the surface, as well as as a result of the discharge of wastewater onto the soil cover during the improper operation of various engineering structures.

The following forms of water erosion are distinguished:

flat (surface), or soil washout,

gully (linear, deep, vertical), or erosion of soil and underlying rocks;

streamlike (rivulet),

coastal (abrasion).

Surface erosion is the process of washing away, removing the most fertile upper layers of soil due to unregulated surface runoff. As a result of surface erosion on arable slopes, there is either a relatively uniform washout of the surface layer of soil or streaky washouts of small depth, which are easily leveled during the next tillage (plowing, cultivation). Repeated washing away of the surface layer and the formation of stream erosion, which are systematically leveled, gradually lead to the formation of soils with a shortened profile, the so-called washed away soils.

The origin of linear erosion is facilitated by rivulet erosion, which is not systematically leveled after the next snowmelt or rainfall, becoming collectors that concentrate surface water flow and developing into typically linear forms of erosion - first into gullies and then into ravines. Erosion with a depth of 0.3-0.5 m to 1.0-1.5 m and a width of 0.5 m to 5 m is called gullies. The latter are a kind of preparation for the ravine, into which they, as a rule, grow without being filled up in a timely manner.

The last stage of development of linear modern erosion is the ravine. All forms of modern linear erosion are classified as erosion. In the process of erosion development, an erosional relief is formed, the nature of which depends on the depth of the erosion base, i.e. on the difference in heights between the highest points from which water flows and the erosion base - a horizontal surface at or below which the earth's surface is not washed away by flowing waters. The depth of the local erosion base is the excess of watershed relief elements above the level of a river, valley or ravine bottom. The deeper the local base, the more destructive the water erosion.

Among the various forms of water erosion, gully erosion causes significant harm to the environment and, first of all, to soils. The environmental damage from ravines is enormous. The ravines are destroying valuable agricultural land. It is estimated that daily soil loss due to the development of ravines reaches 100-200 hectares.

With erosion, called abrasion (collapse of river banks and other bodies of water), the area of ​​arable land and pastures is reduced, and water bodies become silted.

Also, some researchers on this issue distinguish water erosion as a separate type - drip erosion, during which the soil is destroyed by the impact of raindrops. Structural elements (lumps) of soil are destroyed under the influence of the kinetic energy of raindrops and are scattered to the sides. “On slopes, downward movement occurs over a greater distance. When falling, soil particles fall on a film of water, which facilitates their further movement. This type of water erosion is of particular importance in the humid tropics and subtropics.”

A detailed classification and diagnosis of washed away soils of various types was developed by S.S. Sobolev. Soils susceptible to destruction, depending on the degree of erosion, can be divided into the following categories:

slightly eroded (no more than half of the humus horizon is lost, its lower part or podzolic horizon is plowed under),

moderately eroded (more than half or the entire humus horizon is lost, the upper part of the transitional or illuvial horizon is plowed under, giving the soil a brownish tint),

highly eroded (transitional or illuvial horizons are partially lost, the middle or lower part of these horizons is plowed under, the arable layer is brown in color and blocky),

very strongly eroded (transitional or illuvial horizons are completely lost, barren parent rock is plowed up) [cit. according to 3, p.98].

The more soils are eroded, the more they differ from their “normal” analogues in basic parameters: chemical, granulometric composition, physicochemical properties, water, air and thermal regimes, biogenicity.

These are the main types of natural, i.e. natural soil erosion. However, in addition to nature, man and his activities have a negative impact on fertile lands.

The topic of water erosion is also related to the type of irrigation erosion. It is often observed in areas of irrigated agriculture and appears even on small slopes with a significant amount of irrigation flow. At the same time, humus and nutrients available to plants are washed out, and overall soil fertility decreases.

Industrial erosion occurs as a result of mining, especially open-pit mining, construction of residential and industrial buildings, laying of highways, gas and oil pipelines. Mechanical erosion can occur with the widespread use of super-heavy tractors and other equipment without taking into account the possible limit of annual soil self-healing in relation to each natural zone. At the same time, the soil structure is destroyed, its water-physical properties and biological activity deteriorate.

Due to the overload of pastures with livestock, significant areas are subject to pasture (trail) erosion. On farms, grazing of livestock should be strictly regulated, taking into account the number of animals, the type of animals and the overgrazing of pastures.

The classification of types of soil erosion varies among different authors. It all depends on the principle of classification. However, we were able to list the main species identified by researchers in this area.

Methods for protecting soil from water and wind erosion

One of the important factors that has a negative impact on soil productivity is erosion - this is the destruction of the top fertile layer of soil under the influence of natural and anthropogenic forces. The more intensively the land is used, the more effort must be made to maintain its fertility. Irrational land use leads to rapid depletion of soil, which will ultimately make it completely unsuitable for agriculture.

Types of soil erosion

The surface layer of soil is destroyed by water or wind; accordingly, it is customary to distinguish between water and wind soil erosion. Let's take a closer look at each of these processes.

Water erosion occurs mainly on slopes, from which the top fertile soil layer is washed away by melt water or water from irrigation canals. As a result, gullies and ravines begin to form, and very soon the area begins to lose its fertile qualities. Water erosion is usually classified on several grounds:

• Based on the distribution of water flow, they are divided into surface and linear. In the first case, the flow of water washes away only the upper humus layer, in the second, a strong flow of water leads not only to the washing out of the top layer of soil, but also to the destruction of the underlying rocks, in this case it is much more difficult to restore the soil.
• According to the degree, natural and anthropogenic erosion are distinguished. The first occurs under the influence only of natural forces, and, as a rule, it does not have a significant effect on soil fertility. The second arises due to irrational farming, and it can quickly take a plot out of production due to the destruction of the fertile layer.

Wind erosion occurs primarily in steppe regions with large open spaces; it is the weathering of fertile soil particles in areas not protected by vegetation. Wind erosion can cover large areas; it is especially dangerous for dry land masses; most often, areas suffer precisely because of too active human economic activity.

Soil protection from erosion is one of the priority areas of agricultural technology.

It pursues two goals - preventing erosion and weathering of the fertile soil layer and increasing productivity. these goals are inseparable from each other. Today, a wide range of measures has already been developed and successfully applied to protect agricultural land from depletion.

Causes of Soil Erosion

Natural soil erosion is largely related to the climatic characteristics of a given region, while human activity in growing crops can significantly accelerate natural processes.

The rate of damage to the surface layer is influenced by the following factors:

• Features of the climate. The development of water erosion is typical for regions with prolonged heavy rains, as well as with the rapid arrival of spring, accompanied by a sharp melting of large amounts of snow. The resulting meltwater erodes the soil and damages the valuable fertile layer. Wind erosion is typical for flat areas with a dry climate; due to the small amount of precipitation, the soil quickly dries out.
• Features of the relief. The rate of erosion directly depends on the steepness and length of the slopes; in addition, destructive processes develop faster on convex slopes than on concave surfaces. On plains, erosion occurs more quickly where vegetation cover is minimal.
• Soil properties also play an important role in the rate of erosion processes. Chernozems are considered the most stable; such soil practically does not weather or erode. Gray soil, clayey and sandy soil, on the contrary, are characterized by the least stability and quickly collapse under certain conditions.
• The presence of a plant layer. Plant roots guarantee the soil reliable protection from water and wind; in addition, they ensure rapid absorption of moisture and prevent the soil from drying out even in hot weather. Tall plant stems also prevent soil from weathering, as wind speeds near the ground are reduced.
• Human economic activity remains one of the most destructive factors. Uncontrolled grazing of livestock in the same areas, plowing of lands in violation of crop rotation rules. mining - all this leads to damage to the soil layer, and it is extremely difficult to restore it.

Thus, when selecting methods to combat other types of erosion, the causes of its occurrence must be taken into account. Only by eliminating the causes can a sustainable result be achieved and the soil protected.

Methods for protecting soil from water erosion

Soil protection from water erosion is a whole complex of agro-reclamation and hydro-reclamation measures that must be carried out according to a pre-agreed plan.

The range of works on soil protection includes the following main areas:

• Organizational and economic work. These include periodic inspection of fields with the drawing up of plans and maps, a comprehensive assessment of erosion processes, development of an action plan and monitoring of their implementation. Pre-planning is one of the important factors for success in erosion control.
• Agricultural reclamation measures are a system of crop rotation taking into account soil protection. It involves planting perennial crops, placing cultivated plants in strips on slopes, developing and installing a snow retention system to prevent soil from being washed away by melt water. In addition, the measures include the application of mineral and organic fertilizers. The main task at this stage is to minimize the washout of soil by melt water and prevent soil depletion.
• Forest and drainage soil protection. It involves planting forest strips on slopes, constructing channels for draining melt water, terracing slopes, creating dams and artificial reservoirs. These measures make it possible to direct drainage along strictly limited routes and protect the main land mass.

Work to protect soil from water erosion also depends on the level of slope. In areas with a slight slope not exceeding 2 degrees, surface runoff can be easily minimized; to do this, it is enough to sow in transverse stripes or plant plants along the contour.

On fields located at a slope of up to 6 degrees, a wide range of soil protection methods are used: including step plowing, furrowing, digging and other techniques.

With a stronger slope, protective strips of perennial grasses are created on the field. For 40 meters of planting of cultivated plants, the width of the protective grass strip should be at least 7 m. The width of the protective buffer strip depends on the steepness of the slope: the higher it is, the wider the strips should be. Planting row crops on steep slopes is prohibited.

A set of measures to combat water erosion allows you to get good results and ensure the preservation of the soil for many years. The condition of the soil should be periodically monitored and the protective measures applied should be adjusted.

Methods for protecting soil from wind erosion

Soil protection from wind erosion is a set of measures designed to prevent soil weathering and ensure the preservation of the top fertile layer. For this purpose, soil-protective crop rotation is used, which involves placing grain crops and perennial grasses in strips. In addition, protection against erosion requires measures to accumulate moisture and create protective forest buffer strips.

The main way to protect the earth from wind erosion is to create a dense vegetation cover that prevents the gradual weathering of soil particles.

Where wind erosion poses a serious threat to maintaining yields, crop rotation fields are located across the prevailing wind direction; in addition, it is undesirable to locate roads and forest belts along the slopes.

There are several common methods for combating wind erosion:

• Planting bushes of tall crops. Such plants become an effective protective barrier to the wind and significantly reduce its speed and negative impact on the soil. The sowing of perennial grasses and winter crops is expanding, and forage areas are being improved.
• Measures for moisture accumulation. To do this, bushes of tall plants such as mustard or corn are planted. Planting is carried out in mid-July: in this case, the plants grow quickly, but no longer produce seeds. Planting wings allows you to ensure uniform distribution of snow in winter and prevent the negative impact of strong winds on the soil.
• Snow retention using inter-strip snow compaction. It allows you to reduce soil freezing and provide intensive moisture in the spring. This has a positive effect on productivity and protects plant roots from freezing.

Such simple agricultural techniques allow you to get good results and maintain soil fertility. Additionally, to protect against wind erosion, windbreak forest strips are planted; they are located on the borders of fields allocated for crop rotation.

Additional Erosion Control Methods

Most of the methods of combating water and wind soil erosion are preventive in nature: these measures are not aimed at restoring the soil, but at preventing its destruction. Timely implementation of preventive measures helps to avoid the occurrence of pockets of erosion and its further spread through agricultural coals.

In addition to the above, several more effective methods of combating soil erosion are also used in agriculture:

• One of the effective methods of combating water and wind erosion is the construction of anti-erosion terraces. The areas are sown with perennial grasses, the rows are placed across the slopes. Legumes are actively used for this purpose.
• Sodding (another name is green manure). This is a technique for plowing the green mass of plants into the soil; green manure is plowed in during the flowering period. Thus, the soil is enriched with useful organic matter, in addition, its resistance to erosion and weathering increases.
• Strip planting of shrubs across the slope. Protective strips prevent both water and wind erosion; they become a reliable barrier to soil destruction. Forest strips are also planted on the upper boundaries of slopes to protect them from crumbling and erosion, as well as at the bottom of ravines and at the edges of fields.
• Arranging dams and creating artificial reservoirs helps increase soil moisture and protects it from drying out. To maintain soil moisture, harrowing is also carried out in early spring, while a protective mulch layer is introduced into the soil, which also enriches it with organic matter.
• Correcting the process of melt water runoff. For this purpose, methods such as mole cutting, intermittent furrowing, etc. are used.

All these methods can significantly slow down erosion processes and maintain soil fertility. Timely application of complex fertilizers promotes accelerated growth of plants, the root system of which creates an additional powerful barrier to soil destruction. Taking care of the condition of the land will allow you to maintain high yields for many years.

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Water and wind soil erosion

Soil erosion- the process of destruction of soil cover. Soil erosion includes removal, transport and redeposition of soil mass. Depending on the destruction factor, erosion is divided into water and wind (deflation).

Water erosion- the process of destruction of soil cover under the influence of melt, rain or irrigation water.

Based on the nature of the impact on the soil, water erosion is divided into planar and linear.

Planar (surface) erosion- washout of the upper soil horizon under the influence of rain or melt water flowing down the slope. The mechanism of surface erosion is associated with the destructive impact force of raindrops and with the impact of surface runoff of rain and melt water.

Linear (gully) erosion- erosion of soils into depth by a more powerful stream of water flowing down the slope. At the first stage of linear erosion, deep stream erosion (up to 20-35 cm) and gullies (depth from 0.3-0.5 to 1-1.5 m) are formed. Their further development leads to the formation of ravines. Linear erosion leads to the complete destruction of soil.

In mountainous areas, along with the development of normal forms of water erosion, mudflows (mudflows) may occur. They are formed after rapid snowmelt or intense rains, move at high speed and carry away a huge amount of material in the form of fine earth, pebbles and large stones. The fight against them requires the construction of special anti-mudflow structures.

Based on the rate of development, a distinction is made between geological (normal) and accelerated erosion.

Geological (normal) erosion- a slow process of washing away particles from the soil surface covered with natural vegetation, in which the loss of soil is compensated for during soil formation. This type of erosion occurs everywhere, causes virtually no harm and does not require soil protection.

Accelerated erosion occurs when natural vegetation is removed and soil is misused, resulting in a sharp increase in the rate of erosion. This type of erosion leads to a decrease in soil fertility, and sometimes to the complete destruction of soil cover, and requires soil protection.

Wind erosion (deflation) - the process of destruction of soil cover under the influence of wind. Depending on the size of the particles, they can be transported by the wind in suspension, jumping and sliding along the surface. There are dust (black) storms and everyday (local) deflation.

Dust storms repeat once every 3-20 years, carry away up to 15-20 cm of the surface layer of soil. In this case, large soil particles move short distances, stopping at various obstacles and in depressions of the relief. The smallest soil particles (<0,1 и <0,001 мм) в виде воздушной суспензии перемещаются на десятки, сотни и даже ысячи километров.

Everyday Deflation more slowly but regularly destroys the soil. It manifests itself in the form of top erosion and drifting snow. With overhead erosion, soil particles are lifted by the vortex (turbulent) movement of air high up, and with drifting snow they are rolled by the wind along the soil surface or move spasmodically at a small height from the soil.

When rolling and jumping, particles hit and rub against each other, which increases their destruction. This contributes to increased deflation.

Erosion areas. Water erosion is most common in zones of gray forest soils, chernozem, chestnut soils, in agricultural areas of the taiga-forest zone, and in mountainous areas.

Wind erosion is common mainly in areas of insufficient moisture and low relative air humidity: in areas of unstable moisture, in arid areas, in deserts and semi-deserts.

Ecological consequences of erosion.

As a result of erosion, a decrease in soil fertility occurs (with surface water erosion and deflation) or complete destruction of the soil cover (with linear water erosion). The decrease in fertility is associated with the gradual removal of the most fertile upper layer and the inclusion of less fertile lower horizons into the arable horizon. The degree of fertility reduction depends on the degree of washout or deflation.

As a result, erosion worsens

Physical, chemical and biological properties of soil.

The content and supply of humus decreases, and its qualitative composition often deteriorates,

The reserves of nutrients (nitrogen, phosphorus, potassium, etc.) and the content of their mobile forms are reduced.

The structural condition and composition deteriorate, porosity decreases and density increases, which leads to a decrease in water permeability, an increase in surface runoff, a decrease in moisture capacity and reserves of moisture available to plants.

The loss of the upper most humified and structured layer leads to a decrease in the biological activity of soils :

The number of microorganisms and mesofauna decreases,

The microbiological and enzymatic activity of soils decreases.

Besides, water erosion is accompanied by a number of other unfavorable phenomena:

Loss of melt and rain water,

Reducing water reserves in the soil,

Division of fields,

Siltation of rivers, irrigation and drainage systems, and other bodies of water,

Disruption of the road network, etc.

Ultimately, deterioration of the fertility of eroded soils leads to a decrease in the yield of agricultural plants .

Conditions for the development of erosion. There are natural and socio-economic conditions for the development of erosion. In the first case, the natural conditions themselves are predisposed to the manifestation of erosion processes. In the second case, the development of erosion is facilitated by improper human use of land.

Natural conditions include climate (quantity, intensity and size of raindrops; thickness of snow cover and intensity of its melting), relief (steepness, length, shape and exposure of the slope), geological structure of the area (nature of rocks - their susceptibility to erosion, washout and deflation, presence dense underlying rocks), soil conditions (grain size distribution, structure, density and moisture of the upper horizon) and vegetation cover (presence and nature of vegetation cover, presence of turf and litter).