The negative impact of man on the soil environment. Human impact on the lithosphere and soil, their consequences. Industrial and domestic emissions into the environment

II. The concept of an agroecosystem

The concept of "ecosystem" was proposed by the Englishman Arthur Tensley in 1935. Knowledge of the laws of organization of ecosystems allows you to use them or even change them without completely destroying the system of natural connections that have arisen.

The concept of "agroecosystem" as an agricultural version of the ecosystem appeared in the 60s. They designate a piece of territory, an agricultural landscape corresponding to the economy. All its elements are connected not only biologically and geochemically, but also economically. Professor L. O. Karpachevsky in the preface to the Russian translation of the American book "Agricultural Ecosystems" emphasized the dual socio-biological nature of the agro-ecosystem, the structure of which is largely determined by man. For this reason, agroecosystems are among the so-called anthropogenic (i.e., man-made) ecosystems. However, it is still closer to a natural ecosystem than, say, to another variant of anthropogenic ecosystems - urban ones.

Agroecosystems are anthropogenic (i.e., man-made) ecosystems. Man determines their structure and productivity: he plows up part of the land and sows agricultural crops, creates hayfields and pastures in place of forests, and breeds farm animals.

Agroecosystems are autotrophic: their main source of energy is the sun. The additional (anthropogenic) energy that a person uses in soil cultivation and which is spent on the production of tractors, fertilizers, pesticides, etc., does not exceed 1% of the solar energy absorbed by the agroecosystem.

Like a natural ecosystem, an agroecosystem consists of organisms of three main trophic groups: producers, consumers, and decomposers.

Agricultural ecosystems or agroecosystems (AGRES) are among the anthropogenic ecosystems that are closest to natural ones. These ensembles of species are artificial, since the composition of cultivated plants and bred animals is determined by a person who stands at the top of the ecological pyramid and is interested in obtaining the maximum amount of agricultural products: grain, vegetables, milk, meat, cotton, wool, etc. At the same time, AGRES, like natural ecosystems, are autotrophic. The main source of energy for them is the Sun. All anthropogenic energy introduced into the AGRPP, spent on plowing the land, fertilizing, heating livestock premises, is called an anthropogenic energy subsidy (AS). The NPP makes no more than 1% of the total energy budget of AGRES. It is AS that is the cause of the destruction of agricultural resources and environmental pollution, which complicates the solution of the problem of providing FS. Reducing the AC value is the basis for providing FS.

The value of AS in AGRPP can vary over a wide range, and if we correlate it with the amount of energy contained in the finished product, then this ratio will vary from 1/15 to 30/1. In the primitive (but still preserved) gardens of the Papuans, at least 15 calories of food are obtained per calorie of muscle energy, but only one calorie of food is obtained by investing 20-30 calories of energy in intensive agriculture. Of course, such intensive farming makes it possible to obtain 100 quintals of grain per 1 hectare, 6,000 liters of milk from one cow, and more than 1 kg of daily weight gain in animals fed for meat. However, the price of these successes is too high. The destruction of agricultural resources, which has assumed alarming proportions in the last 20-30 years, is contributing to the approach of the coming ecological crisis.

The "Green Revolution" that took place in the 60-70s of our century, when, thanks to her father, the Nobel Prize winner N. Berlaug, dwarf varieties appeared on the fields with a yield exceeding that in traditional crops by 2-4 times, and new breeds of livestock - "biotechnological monsters", dealt the most tangible blow to the biosphere. At the same time, by the beginning of the 1980s, grain production had stabilized and there was even a tendency to decrease due to the loss of natural soil fertility and a decrease in the effectiveness of fertilizers. At the same time, the world's population continues to grow rapidly, and as a result, the amount of grain produced in the world in terms of one person began to decline.

III. urban ecosystems

Urban ecosystems are heterotrophic, the proportion of solar energy fixed by urban plants or solar panels located on the roofs of houses is insignificant. The main sources of energy for the enterprises of the city, heating and lighting of the apartments of the townspeople are located outside the city. These are deposits of oil, gas, coal, hydro and nuclear power plants.

The city consumes great amount water, only a small part of which a person uses for direct consumption. The bulk of the water is spent on production processes and for household needs. Personal water consumption in cities ranges from 150 to 500 liters per day, and taking into account industry, one citizen accounts for up to 1000 liters per day.

The water used by cities is returned to nature in a polluted state - it is saturated with heavy metals, oil residues, complex organic substances like phenol, etc. It may contain pathogens. The city emits toxic gases and dust into the atmosphere, concentrates toxic waste in landfills, which, with spring water flows, enter aquatic ecosystems.

Plants, as part of urban ecosystems, grow in parks, gardens, and lawns, their main purpose is to regulate the gas composition of the atmosphere. They release oxygen, absorb carbon dioxide and clean the atmosphere from harmful gases and dust that enter it during operation. industrial enterprises and transport. Plants are also of great aesthetic and decorative value.

Animals in the city are represented not only by species common in natural ecosystems (birds live in parks: redstart, nightingale, wagtail; mammals: voles, squirrels and representatives of other groups of animals), but also by a special group of urban animals - human companions. It includes birds (sparrows, starlings, pigeons), rodents (rats and mice), and insects (cockroaches, bedbugs, moths). Many animals associated with humans feed on garbage in garbage dumps (jackdaws, sparrows). These are the city nurses. The decomposition of organic waste is accelerated by fly larvae and other animals and microorganisms.

The main feature of the ecosystems of modern cities is that the ecological balance is disturbed in them. All processes of regulating the flow of matter and energy a person has to take over. A person must regulate both the consumption of energy and resources by the city - raw materials for industry and food for people, and the amount of toxic waste entering the atmosphere, water and soil as a result of industry and transport. Finally, it also determines the size of these ecosystems, which in developed countries, and in recent years in Russia, are rapidly "spreading" due to suburban cottage construction. Low-rise areas reduce the area of forests and agricultural land, their "spreading" requires the construction of new highways, which reduces the proportion of ecosystems capable of producing food and cycling oxygen.

IV. Industrial pollution

In urban ecosystems, industrial pollution is the most dangerous for nature.

Chemical pollution of the atmosphere. This factor is one of the most dangerous for human life. The most common pollutants are sulfur dioxide, nitrogen oxides, carbon monoxide, chlorine, etc. In some cases, out of two or relatively few, relatively few hazardous substances emitted into the atmosphere, toxic compounds can be formed under the influence of sunlight. Ecologists number about 2,000 air pollutants.

The main sources of pollution are thermal power plants. Boiler houses, oil refineries and vehicles also heavily pollute the atmosphere.

Chemical pollution of water bodies. Enterprises dump oil products, nitrogen compounds, phenol and many other industrial wastes into water bodies. During oil production, water bodies are polluted with saline species, oil and oil products are also spilled during transportation. In Russia, the lakes of the North of Western Siberia suffer the most from oil pollution. In recent years, the danger to aquatic ecosystems of domestic wastewater from urban sewers has increased. In these effluents, the concentration of detergents has increased, which microorganisms decompose with difficulty.

As long as the amount of pollutants emitted into the atmosphere or discharged into rivers is small, ecosystems themselves are able to cope with them. With moderate pollution, the water in the river becomes almost clean after 3-10 km from the source of pollution. If there are too many pollutants, ecosystems cannot cope with them and irreversible consequences begin. The water becomes undrinkable and dangerous to humans. Polluted water is not suitable for many industries.

Pollution of the soil surface with solid waste. City dumps of industrial and household waste occupy large areas. Garbage may contain toxic substances such as mercury or other heavy metals, chemical compounds that dissolve in rain and snow water and then enter water bodies and groundwater. Can get into garbage and devices containing radioactive substances.

The surface of the soil can be polluted by ash deposited from the smoke of coal-fired thermal power plants, cement factories, refractory bricks, etc. To prevent this contamination, special dust collectors are installed on the pipes.

Chemical pollution of groundwater. Groundwater currents transport industrial pollution over long distances, and it is not always possible to determine their source. The cause of pollution may be the washing out of toxic substances by rain and snow water from industrial landfills. Groundwater pollution also occurs during oil production using modern methods, when, in order to increase the return of oil reservoirs, salt water is re-injected into the wells, which has risen to the surface along with the oil during its pumping. Salt water enters the aquifers, the water in the wells becomes bitter and undrinkable.

Noise pollution. The source of noise pollution can be an industrial enterprise or transport. Especially heavy dump trucks and trams produce a lot of noise. Noise affects the human nervous system, and therefore noise protection measures are taken in cities and enterprises. Railway and tram lines and roads, along which freight transport passes, need to be moved from the central parts of cities to sparsely populated areas and create green spaces around them that absorb noise well. Planes should not fly over cities.

Noise is measured in decibels. Clock ticking - 10 dB, whisper - 25, noise from a busy highway - 80, aircraft takeoff noise - 130 dB. The pain threshold of noise is 140 dB. On the territory of residential development during the day, the noise should not exceed 50-66 dB.

Also, pollutants include: contamination of the soil surface with overburden and ash dumps, biological pollution, thermal pollution, radiation pollution, electromagnetic pollution.

V. Soil pollution

Soil - the top layer of land, formed under the influence of plants, animals, microorganisms and climate from the parent rocks on which it is located. This is an important and complex component of the biosphere, closely related to its other parts.

Under normal natural conditions, all processes occurring in the soil are in balance. But often a person is to blame for the violation of the equilibrium state of the soil. As a result of the development of human activities, pollution, changes in the composition of the soil and even its destruction occur.

fertile layer Soil takes a very long time to form. At the same time, tens of millions of tons of nitrogen, potassium, and phosphorus, the main components of plant nutrition, are removed from the soil every year along with the harvest. The main factor of soil fertility - humus (humus) is contained in chernozems in an amount of less than 5% of the mass of the arable layer. On poor soils, humus is even less. In the absence of soil replenishment with nitrogen compounds, its reserve can be used up in 50-100 years. This does not happen, since the culture of agriculture provides for the introduction of organic and inorganic (mineral) fertilizers into the soil.

The nitrogen fertilizers introduced into the soil are used by plants by 40-50%. The rest (about 20%) is reduced by microorganisms to gaseous substances - N 2 , N 2 O - and volatilizes in the atmosphere or is washed out of the soil. Thus, mineral nitrogen fertilizers do not have a long-term effect and therefore they have to be applied annually. Unfavorable changes in the soil also occur as a result of incorrect crop rotations, i.e. annual sowing of the same crops, such as potatoes. The inclusion of legumes in the crop rotation enriches the soil with nitrogen. Clover and alfalfa crops, due to the binding of N 2 by symbiotic nodule bacteria, make it possible to retain up to 300 kg of nitrogen per 1 ha in the soil. Crop rotations are also necessary to combat herbivorous nematode worms, which significantly reduce yields. For example, bulb-garlic nematodes can reduce onion yields by 50%.

Pollution of the soil cover with mercury (with pesticides and waste from industrial enterprises), lead (from lead smelting and from vehicles), iron, copper, zinc, manganese, nickel, aluminum and other metals (near large centers of ferrous and non-ferrous metallurgy), radioactive elements ( as a result of precipitation from atomic explosions or during the removal of liquid and solid waste from industrial enterprises, nuclear power plants or research institutes related to the study and use of atomic energy), persistent organic compounds used as pesticides. They accumulate in soil and water and, most importantly, are included in ecological food chains: they pass from soil and water to plants, animals, and eventually enter the human body with food. The inept and uncontrolled use of any fertilizers and pesticides leads to disruption of the circulation of substances in the biosphere.

Anthropogenic changes in soils include erosion(from the Latin erosio - to corrode). The destruction of forests and natural grass cover, repeated plowing of the land without observing the rules of agricultural technology lead to soil erosion - the destruction and washing away of the fertile layer by water and wind. The most destructive water erosion is also widespread. It occurs on the slopes and develops with improper cultivation of the land. Together with melt and rainwater, millions of tons of soil are annually carried away from the fields into rivers and seas.

Wind erosion is most pronounced in the southern steppe regions of our country. It occurs in areas with dry bare soil, with sparse vegetation. Excessive grazing in the steppes and semi-deserts contributes to wind erosion and the rapid destruction of the grass cover. It takes 250-300 years to restore a layer of soil 1 cm thick under natural conditions.

Significant areas with formed soils are withdrawn from agricultural circulation due to the open method of mining minerals occurring at shallow depths.

VI. Anthropogenic impact on forests, forest management

In the development of anthropogenic impact on the forests of the European North of Russia, two main periods can be distinguished: before the start of intensive industrial development of the forest resources of the North, focused on the needs of other regions and exports, and after. Of course, the time boundary between these periods is quite vague, and changes from the southwest to the northeast (from regions that are more populated and close to large economic centers to less populated and more remote). In some parts of the territory under consideration, intensive industrial development of forest resources began already in the 17th - 18th centuries (for example, in the Staraya Russa region due to the active development of salt production or in the middle and southern Urals due to the development of charcoal metallurgy). However, in most of the territory under consideration, any intensive industrial development of forest resources begins in the middle of the 19th century and is associated with the beginning of a rapid growth in the export of forest materials from northern ports to European countries.

Each of these periods was characterized by its own characteristics of the impact of human economic activity on the taiga nature. It cannot be said unequivocally that the level of human impact on the natural ecosystems of the North in the first period, before the start of intensive forest exploitation, was negligible. Already in the very initial period of human settlement of the modern taiga territory, it was at least a significant additional source of forest fires - and in this way has already made a significant contribution to the formation of taiga ecosystems. Subsequently, a significant role in the formation of taiga landscapes was played by slash-and-burn agriculture and clearing of hayfields in the floodplains of taiga rivers, logging for local economic needs, hunting and fishing, and many other types of economic activities related to subsistence farming. northern villages and cities. Many forms and elements of the economy that were formed during this first period of economic development by man of the territory of the North were preserved during most of the next - industrial - period. Thus, slash-and-burn agriculture existed in the North until the 1930s. XX century and finally stopped mainly in connection with the collectivization and extermination of individual peasants. The use of small hayfields along the floodplains of small taiga rivers and streams continues in some places at the present time, although the vast majority of such hayfields have also been gradually abandoned, starting from the 1920s. The system of hunting huts-winter huts exists and in some places is partially updated to the present, although it no longer has the former density and former significance and is not so often used by the local population. Obvious traces of "pre-industrial" human economic activity - abandoned and forested plots of undercuts or small forest hayfields, the remains of old hunting huts, and sometimes even small settlements - can now be found in places in the very center of now wild and absolutely uninhabited taiga territories.

Despite the fact that human economic activity in the first period - before the start of intensive forest exploitation - was a very important factor influencing the structure and dynamics of taiga territories, in this paper all this activity is considered as a historical factor in the formation of the taiga, and not as an anthropogenic disturbance (see .chapter "Background anthropogenic impacts"). Of course, the anthropogenic infrastructure created at that time and which has existed to date (settlements, transport routes, industrial centers) was excluded from potential intact forest areas.

A significantly greater impact on the natural ecosystems of the North was associated with the subsequent period of development of economic activity - with the intensive industrial development of the forest resources of the taiga.

Used Books

1. www.omsk.edu.ru/schools/sch004/ecolog/lit.htm.

2. Garin V.M., Klenova I.A., Kolesnikov V.I. Ecology for technical universities. Rostov-on-Don, Phoenix Publishing House, 2001

3. Stepanovskikh A.S. General ecology: A textbook for universities - M: UNITI-DANA, 2001.

Plan

Introduction

2. Human influence on the soil

3. Soil erosion

3.1 Causes and types of erosion

3.2 Soil erosion control

4. Ways of pollutants entering the soil and classification of soil pollution

5. Soil contamination with pesticides

6. Soil aridization

7. Land degradation

8. Protection of land resources

Conclusion

Bibliography

Introduction

At present, the problem of the interaction of human society with nature has become particularly acute. It becomes indisputable that the solution to the problem of preserving the quality of human life is unthinkable without a certain understanding of modern environmental issues: preservation of the evolution of living, hereditary substances (gene pool of flora and fauna), preservation of the purity and productivity of natural environments (atmosphere, hydrosphere, soils, forests, etc.), ecological regulation of anthropogenic pressure on natural ecosystems within their buffer capacity, preservation of ozone layer, trophic chains in nature, the circulation of substances and others.

The soil cover of the Earth is the most important component of the Earth's biosphere. It is the soil shell that determines many processes occurring in the biosphere.

The main reasons for the decrease in the area of agricultural land are manifestations of soil erosion, insufficiently thought out land acquisition for non-agricultural needs, flooding, flooding and waterlogging, overgrowing with forests and shrubs, desertification and alienation for industrial and urban construction.

The most important significance of soils is the accumulation of organic matter, various chemical elements, and energy. The soil cover functions as a biological absorber, destroyer and neutralizer of various contaminants. If this link of the biosphere is destroyed, then the existing functioning of the biosphere will be irreversibly disrupted. That is why it is extremely important to study the global biochemical significance of the soil cover, its state of the art and changes under the influence of anthropogenic activities.

1. Soil: meaning and structure

An important stage in the development of the biosphere was the emergence of such a part of it as the soil cover. With the formation of a sufficiently developed soil cover, the biosphere becomes an integral complete system, all parts of which are closely interconnected and dependent on each other.

The soil cover is the most important natural formation. Its role in the life of society is determined by the fact that the soil is the main source of food, providing 95-97% of the food resources for the world's population. The land area of the world is 129 million km 2 or 86.5% of the land area. Arable land and perennial plantations as part of agricultural land occupy about 15 million km 2 (10% of land), hayfields and pastures - 37.4 million km 2 (25% of land). The general arable suitability of lands is estimated by various researchers in different ways: from 25 to 32 million km 2.

Ideas about the soil as an independent natural body with special properties appeared only at the end of the 19th century, thanks to V.V. Dokuchaev, the founder of modern soil science. He created the doctrine of the zones of nature, soil zones, factors of soil formation.

Soil is a special natural formation that has a number of properties inherent in animate and inanimate nature. Soil is the environment where most of the elements of the biosphere interact: water, air, living organisms. The soil can be defined as a product of weathering, reorganization and formation of the upper layers of the earth's crust under the influence of living organisms, the atmosphere and metabolic processes. The soil consists of several horizons (layers with the same characteristics), resulting from the complex interaction of parent rocks, climate, plant and animal organisms (especially bacteria), and terrain. All soils are characterized by a decrease in the content of organic matter and living organisms from the upper soil horizons to the lower ones.

Horizon Al is dark-colored, contains humus, is enriched in minerals and is of the greatest importance for biogenic processes.

Horizon A 2 - eluvial layer, usually has an ash, light gray or yellowish gray color.

Horizon B is an eluvial layer, usually dense, brown or brown in color, enriched in colloidal dispersed minerals.

Horizon C is the parent rock altered by soil-forming processes.

Horizon D is the parent rock.

The surface horizon consists of vegetation residues that form the basis of humus, the excess or deficiency of which determines the fertility of the soil. Humus is the organic matter most resistant to decomposition and therefore persists after the main decomposition process has already been completed. Gradually, humus also mineralizes to inorganic matter. Mixing humus with soil gives it structure. The layer enriched with humus is called arable, and the underlying layer is called subarable. The main functions of humus are reduced to a series of complex metabolic processes, which involve not only nitrogen, oxygen, carbon and water, but also various mineral salts present in the soil. Under the humus horizon there is a subsoil layer corresponding to the leached part of the soil, and a horizon corresponding to the parent rock.

Soil texture is the shape and size of the lumps into which it breaks up. Best structure- small lumpy. Inside the lumps, conditions are formed for the activity of humifying microorganisms that form humus, and between the lumps - for microorganisms that decompose humus to mineral compounds available to plants.

The soil consists of three phases: solid, liquid and gaseous. The solid phase is dominated by mineral formations and various organic substances, including humus, or humus, as well as soil colloids of organic, mineral or organomineral origin. The liquid phase of the soil, or soil solution, is water with organic and mineral compounds dissolved in it, as well as gases. The gas phase of the soil is "soil air", which includes gases that fill the water-free pores.

An important component of the soil, contributing to its change physical and chemical properties, is its biomass, which includes, in addition to microorganisms (bacteria, algae, fungi, unicellular organisms), also worms and arthropods.

It follows from the above that the soil includes mineral particles, detritus, many living organisms, that is, the soil is a complex ecosystem that ensures plant growth. Soils are a slowly renewable resource. Soil formation processes proceed very slowly, at a rate of 0.5 to 2 cm per 100 years. The thickness of the soil is small: from 30 cm in the tundra to 160 cm in the western chernozems. One of the features of the soil - natural fertility - is formed for a very long time, and the destruction of fertility occurs in just 5-10 years. It follows from the above that the soil is less mobile than other abiotic components of the biosphere.

soil erosion pollution pesticide

Human influence on the soil

Economic activity Man is currently becoming the dominant factor in the destruction of soils, the decrease and increase in their fertility. Under the influence of man, the parameters and factors of soil formation change - reliefs, microclimate, reservoirs are created, melioration is carried out.

The main property of the soil is fertility. It has to do with soil quality. In the destruction of soils and the decrease in their fertility, several processes are distinguished.

Special place among the soils are arable lands, i.e., lands that provide human nutrition. According to the conclusion of scientists and experts, at least 0.1 ha of soil should be cultivated to feed one person. The growth in the number of inhabitants of the Earth is directly related to the area of arable land, which is steadily declining. So in the Russian Federation over the past 27 years, the area of agricultural land has decreased by 12.9 million hectares, of which arable land - by 2.3 million hectares, hayfields - by 10.6 million hectares. The reasons for this are the violation and degradation of the soil cover, the allocation of land for the development of cities, towns and industrial enterprises.

Over large areas, there is a decrease in soil productivity due to a decrease in the content of humus, the reserves of which have decreased by 25-30% in the Russian Federation over the past 20 years, and the annual loss is 81.4 million tons. Today, the earth can feed 15 billion people. Careful and competent handling of land today has become the most urgent problem.

Anthropogenic impact on the soil is divided into several types:

1) erosion (wind and water);

2) pollution;

3) desertification;

4) alienation of land for industrial and municipal construction, as well as secondary salinization and waterlogging.

The agricultural development of Russia is 13%, 2/3 of this territory is arable land (131.7 million hectares), but this area is decreasing from year to year. Every year, more than 1 million hectares of agricultural use are lost as a result of erosion and 100 thousand hectares are “eaten up” by ravines. Every year, Russian soils lose more than 0.5 tons of humus per 1 ha. Of the 5.9 million hectares of irrigated land, more than half of these soils are secondarily saline and produce extremely low yields. Every fourth hectare of arable land has acidic soils due to acid rain and fertilizer application, which also reduces the yield. The area of arable land is shrinking as a result of the "spreading" of cities, the construction of roads and industrial facilities.

In the process of human activity, there is a diverse impact on the lithosphere and soil: asphalting, mining, agricultural processing, construction of communication lines, placement of production facilities, etc.

Annual mining volumes are approximately 100 billion tons of rock mass. This leads to increased impact on the lithosphere. If such rates of production continue, then in the short term, the volume of mining production will double every ten years.

Due to the depletion of many types of resources near the earth's surface, production is moving to deeper horizons. So, open iron ore quarries have a depth of 150 m or more, and some - up to 500 m. The quarries are surrounded by waste rock dumps, the height of which sometimes reaches 100 m. Over 2 billion m 3 are added annually to the existing dumps. In countries where underground mining has been carried out for several centuries, in particular in the Czech Republic, the lower levels of the mines have sunk to a depth of 1300 - 1500 m. In South Africa and India, gold mines have reached a depth of 4 km.

Intensive development of minerals leads to the transformation natural conditions: groundwater levels, modes of their movement, which causes subsidence and shifts of the earth's surface, the formation of cracks and failures.

The area of land resources in the world is 129 million km 2 or 86.5% of the land area. Arable land and perennial plantations as part of agricultural land occupy about 15 million km 2 (10.4% of land) or about 3% of the entire surface of the globe, per capita this is about 0.5 ha, hayfields and pastures occupy 37, 4 million km 2 (25% of land). The general arable suitability of lands is estimated by various researchers in different ways: from 25 to 32 million km 2.

The soil is very sensitive to the impact of anthropogenic factors and is most often subjected to destruction. In the destruction of soils and a decrease in their fertility, the following processes are distinguished.

Sushi aridization- a complex of processes for reducing the humidity of vast areas and the resulting reduction in the biological productivity of ecological systems. Under the influence of primitive agriculture, the irrational use of pastures, and the indiscriminate use of technology on the lands, the soils turn into deserts.

Incorrect land use practices lead to soil erosion(from the Latin erosio - corrosive or erodere - corrode), which is the destruction, demolition or washing away of the soil cover by wind or water. This destroys the most fertile topsoil. To create this layer with a thickness of 18 cm, nature spent at least 1400-1700 years, since soil formation proceeds at a rate of approximately 0.5-2 cm per 100 years. The destruction of this layer by erosion can occur in 20-30 years. Grain harvest on eroded soils is 3-4 times lower than usual.

Soil erosion can be wind, water, technical, irrigation.

wind erosion occurs most often in spring at wind speeds
15-20 m / s, when the plants have not yet begun to grow. Moisture reduces the harmful effects of wind. In arid regions, wind erosion results in dust storms. They are repeated after 3-5, sometimes 10 years and demolish a layer of soil up to 25 cm thick, destroying crops. Wind erosion is characterized by the removal of the smallest parts by the wind. Wind erosion contributes to the destruction of vegetation in areas with insufficient moisture, strong winds, continuous grazing.

water erosion represents the flushing of the soil by melt or storm water. It leads to the formation of ravines in slightly hilly terrain. Soil erosion in mountainous areas poses a great danger, where it can cause mudflows. Water erosion is noted at a steepness of already 1-2 °. Water erosion contributes to the destruction of forests, plowing on the slope.

technical erosion associated with the destruction of the soil under the influence of transport, earthmoving machines and technology.

Irrigation erosion develops as a result of violation of the rules of irrigation in irrigated agriculture. Soil salinization is mainly associated with these disturbances. Currently, at least 50% of the area of irrigated land is saline, and millions of previously fertile lands have been lost. A special place among the soils is occupied by arable land, that is, land that provides human nutrition. According to the conclusion of scientists and experts, at least 0.1 ha of soil should be cultivated to feed one person. The growth in the number of inhabitants of the Earth is directly related to the area of arable land, which is steadily declining.

The soil as an object of protection and control has a number of specific features. First of all, the soil is much less mobile than, for example, atmospheric air or surface water, and in this regard, it practically does not have such a powerful natural self-purification factor inherent in other media as dilution. Anthropogenic pollution that got into the soil accumulates, and the effects are summed up.

The intensive development of industrial production leads to an increase in industrial waste, which, together with household waste, significantly affects the chemical composition of the soil, causing a deterioration in its quality. Severe soil contamination with heavy metals, together with zones of sulfur pollution formed during the combustion of coal, lead to a change in the composition of trace elements and the emergence of man-made deserts.

A change in the content of microelements in the soil immediately affects the health of herbivores and humans, leads to metabolic disorders, causing various endemic diseases of a local nature. For example, a lack of iodine in the soil leads to thyroid disease, a lack of calcium in drinking water and food - to damage to the joints, their deformation, growth retardation.

Soil pollution pesticides, heavy metal ions leads to contamination of agricultural crops and, accordingly, food products based on them.

So, if crops are grown with a high natural content of selenium, then sulfur in amino acids (cysteine, methionine) is replaced by selenium. The resulting "selenium" amino acids can lead to poisoning of animals and humans. The lack of molybdenum in the soil leads to the accumulation of nitrates in plants; in the presence of natural secondary amines, a sequence of reactions begins that can initiate the development of cancer in warm-blooded animals.

Soil always contains carcinogenic (chemical, physical, biological) substances that cause tumor diseases in living organisms, incl. and cancerous. The main sources of regional soil contamination with carcinogenic substances are vehicle emissions, emissions from industrial enterprises, and oil products.

Anthropogenic interference can increase the concentration of natural substances or introduce new substances that are foreign to the environment, such as pesticides, heavy metal ions. Therefore, the concentration of these substances (xenobiotics) should be determined both in environmental objects (soil, water, air) and in food products. The maximum allowable limits for the presence of pesticide residues in food are different in different countries and depend on the nature of the economy (import-export of food), as well as on the habitual diet of the population.

With an insufficiently thought-out anthropogenic impact and a violation of balanced natural ecological relationships, undesirable processes of humus mineralization quickly develop in soils, acidity or alkalinity increases, salt accumulation increases, restoration processes develop - all this sharply worsens soil properties, and in extreme cases leads to local destruction of the soil cover. The high sensitivity and vulnerability of the soil cover are due to the limited buffer capacity and resistance of soils to the effects of forces that are not characteristic of it in ecological terms.

Soil pollution with oil products is becoming more and more widespread, the influence of nitric and sulfuric acids of technogenic origin is increasing, leading to the formation of technogenic deserts in the vicinity of some industrial enterprises.

Unbalanced plant nutrition causes the emergence of more and more pests, such as rust fungi, snails, aphids, and weeds that are difficult to eradicate.

Restoration of disturbed soil cover requires a long time and large investments.

Pesticides as a polluting factor. The discovery of pesticides - chemical means of protecting plants and animals from various pests and diseases - is one of the most important achievements. modern science. Today in the world on 1 hectare. applied 300 kg. chemicals. However, as a result of long-term use of pesticides in agriculture, medicine (vector control), almost universally there is a decrease in efficiency due to the development of resistant pest races and the spread of "new" pests whose natural enemies and competitors have been destroyed by pesticides. At the same time, the effect of pesticides began to manifest itself on a global scale. Of the huge number of insects, only 0.3% or 5 thousand species are harmful. Pesticide resistance has been found in 250 species. This is exacerbated by the phenomenon of cross-resistance, which consists in the fact that increased resistance to the action of one drug is accompanied by resistance to compounds of other classes. From a general biological point of view, resistance can be considered as a change in populations as a result of the transition from a sensitive strain to a resistant strain of the same species due to selection caused by pesticides. This phenomenon is associated with genetic, physiological and biochemical rearrangements of organisms. Excessive use of pesticides (herbicides, insecticides, defoliants) negatively affects soil quality. In this regard, the fate of pesticides in soils and the possibilities and possibilities of neutralizing them by chemical and biological methods are being intensively studied. It is very important to create and use only drugs with a short lifespan, measured in weeks or months. Some progress has already been made in this area and drugs with a high rate of destruction are being introduced, but the problem as a whole has not yet been resolved.

Acid atmospheric impacts on land. One of the most acute global problems of today and the foreseeable future is the problem of increasing acidity of precipitation and soil cover. Areas of acidic soils do not know droughts, but their natural fertility is lowered and unstable; they are rapidly depleted and yields are low. Acid rain causes not only acidification of surface waters and upper soil horizons. Acidity with downward water flows extends to the entire soil profile and causes significant acidification of groundwater. Acid rain occurs as a result of human activities, accompanied by the emission of colossal amounts of oxides of sulfur, nitrogen, carbon. These oxides, entering the atmosphere, are transported over long distances, interact with water and turn into solutions of a mixture of sulfurous, sulfuric, nitrous, nitric and carbonic acids, which fall in the form of "acid rain" on land, interacting with plants, soils, waters.

Soil compaction. Soil compaction is the greatest danger. It is the cause of soil erosion, which in many agricultural areas now reaches more than 25 tons / ha per year, which means that the fertile arable layer will be demolished within the life of one generation. Soil compaction also prevents rainwater from penetrating the soil, so that even 10 to 20 days of no rain causes plants to become severely dehydrated. Soil compaction leads to the use of ever more powerful and expensive tractors in combination with larger agricultural implements and mechanisms, which together accelerate soil compaction even more.

Intensive development of minerals leads to the transformation of natural conditions: groundwater levels, modes of their movement, which causes subsidence and shifts of the earth's surface, the formation of cracks and failures.

Soil erosion can be wind, water, technical, irrigation.

wind erosion occurs most often in spring at wind speeds of 15-20 m/s, when the plants have not yet begun to grow. Moisture reduces the harmful effects of wind. In arid regions, wind erosion results in dust storms. They are repeated after 3-5, sometimes 10 years and demolish a layer of soil up to 25 cm thick, destroying crops. Wind erosion is characterized by the removal of the smallest parts by the wind. Wind erosion contributes to the destruction of vegetation in areas with insufficient moisture, strong winds, continuous grazing.

technical erosion associated with the destruction of the soil under the influence of transport, earth-moving machines and equipment.

Soil pollution pesticides, heavy metal ions leads to contamination of agricultural crops and, accordingly, food products based on them.

Unbalanced plant nutrition causes the emergence of more and more pests, such as rust fungi, snails, aphids, and weeds that are difficult to eradicate.

Restoration of disturbed soil cover requires a long time and large investments.

Pesticides as a polluting factor. The discovery of pesticides - chemical means of protecting plants and animals from various pests and diseases - is one of the most important achievements of modern science. Today in the world on 1 hectare. applied 300 kg. chemicals. However, as a result of long-term use of pesticides in agricultural medicine (vector control), there is almost universally a decline in effectiveness due to the development of resistant pest strains and the spread of "new" pests whose natural enemies and competitors have been destroyed by pesticides. At the same time, the effect of pesticides began to manifest itself on a global scale. Of the huge number of insects, only 0.3% or 5 thousand species are harmful. Pesticide resistance has been found in 250 species. This is exacerbated by the phenomenon of cross-resistance, which consists in the fact that increased resistance to the action of one drug is accompanied by resistance to compounds of other classes. From a general biological point of view, resistance can be considered as a change in populations as a result of the transition from a sensitive strain to a resistant strain of the same species due to selection caused by pesticides. This phenomenon is associated with genetic, physiological and biochemical rearrangements of organisms. Excessive use of pesticides (herbicides, insecticides, defoliants) negatively affects soil quality. In this regard, the fate of pesticides in soils and the possibilities and possibilities of neutralizing them by chemical and biological methods are being intensively studied. It is very important to create and use only drugs with a short lifespan, measured in weeks or months. Some progress has already been made in this area and drugs with a high rate of destruction are being introduced, but the problem as a whole has not yet been resolved.

The impact of human society on the soil cover is one of the aspects of the general influence of man on environment.

Throughout history, the impact of human society on the soil cover has continuously increased. In distant times, vegetation was cut down by countless herds and turf was trampled on a vast territory of arid landscapes. Deflation (destruction of soils under the influence of wind) completed the destruction of soils. In more recent times, as a result of non-drainage irrigation, tens of millions of hectares of fertile soils have turned into saline lands and salty deserts. In the 20th century large areas of highly fertile floodplain soils have been flooded or swamped as a result of the construction of dams and reservoirs on large rivers. However, no matter how great the phenomena of soil destruction, this is only a small part of the results of the impact of human society on the soil cover of the Earth. The main result of human impact on the soil is a gradual change in the process of soil formation, an ever deeper regulation of the processes of the cycle of chemical elements and the transformation of energy in the soil.

One of the most important factors of soil formation the vegetation of the world's land has undergone a profound change. Over the course of history, the area of forests has more than halved. Ensuring the development of plants useful to him, man has replaced natural biocenoses with artificial ones on a significant part of the land. The biomass of cultivated plants (unlike natural vegetation) does not completely enter the cycle of substances in a given landscape. A significant part of cultivated vegetation (up to 80%) is removed from the place of growth. This leads to the depletion of reserves in the soil of humus, nitrogen, phosphorus, potassium, microelements and, as a result, to a decrease in soil fertility.

In remote times, due to the excess of land in relation to a small population, this problem was solved by leaving the cultivated area for a long time after the removal of one or more crops. Over time, the biogeochemical balance in the soil was restored and the site could be cultivated again.

In the forest belt, slash-and-burn was used an agricultural system in which the forest was burned, and the liberated area, enriched with ash elements of the burnt vegetation, was sown. After exhaustion, the cultivated area was abandoned and a new one was burned out. The harvest in this type of farming was provided by the supply of mineral nutrients with ash obtained by burning woody vegetation on the spot. Large labor costs for clearing paid off with very high yields. The cleared area was used for 13 years on sandy soils and up to 58 years on loamy soils, after which it was left to overgrow with forest or used for some time as hayfield or pasture. If after that such a plot ceased to be subjected to any human impact (cutting, grazing), then within 40-80 years (in the center and south of the forest belt) the humus horizon in it was restored. For soil restoration in the conditions of the north of the forest zone, a two to three times longer period of time was required.

The impact of the slash-and-burn system led to soil exposure, increased surface runoff and soil erosion, leveling of the microrelief, and depletion of soil fauna. Although the area of cultivated plots was relatively small and the cycle lasted a long time, for hundreds and thousands of years vast territories were deeply transformed by undercutting. It is known, for example, that in Finland for the 1819 centuries. (i.e. for 200 years) 85% of the territory passed through the subcut.

In the south and in the center of the forest zone, the consequences of the slash-and-slash system were particularly acute in the massifs of sandy soils, where primary forests were replaced by specific forests dominated by Scots pine. This led to the retreat to the south of the northern boundaries of the ranges of broad-leaved tree species (elm, linden, oak, etc.). In the north of the forest zone, the development of domestic reindeer husbandry, accompanied by increased burning of forests, led to the development of a tundra zone from the forest tundra or northern taiga, which, judging by the finds of large trees or their stumps, reached the shores of the Arctic Ocean as early as the 18-19th century.

Thus, in the forest belt, agriculture has led to the most profound changes in the living cover and the landscape as a whole. Agriculture was apparently the leading factor in the wide distribution of podzolic soils in the forest belt of Eastern Europe. It is possible that this powerful factor in the anthropogenic transformation of natural ecosystems had a certain effect on the climate as well.

In steppe conditions, the most ancient farming systems were fallow and shifting. With the fallow system, the used plots of land after depletion were left for a long time, with the shifting system for a shorter one. Gradually, the amount of free land decreased, the period of fallow (break between crops) was reduced and, in the end, reached one year. This is how the fallow system of agriculture with a two- or three-field crop rotation arose. However, such increased exploitation of the soil without fertilization and with a low level of agricultural technology contributed to a gradual decrease in yield and product quality.

Vital necessity has put human society before the task of restoring soil resources. From the middle of the last century began industrial production mineral fertilizers, the introduction of which compensated for the nutrients of plants alienated with the harvest.

Population growth and limited areas suitable for agriculture brought to the fore the problem of melioration (improvement) of soils. Land reclamation is aimed primarily at optimizing the water regime. Territories of excessive moisture and swamping are drained, in arid regions - artificial irrigation. In addition, soil salinization is being combated, acidic soils are being limed, salt licks are being gypsumed, and areas are being restored and recultivated. mine workings, quarries, dumps. Land reclamation also extends to high-quality soils, raising their fertility even higher.

As a result of human activity, completely new types of soils have arisen. For example, as a result of thousands of years of irrigation in Egypt, India, and the states of Central Asia, powerful artificial alluvial soils with a high supply of humus, nitrogen, phosphorus, potassium and trace elements have been created. On the vast territory of the loess plateau of China, special anthropogenic soils have been created by the labor of many generations kheilutu . In some countries, liming of acidic soils was carried out for more than a hundred years, which were gradually transformed into neutral ones. The soils of the vineyards of the southern coast of Crimea, which have been used for more than two thousand years, have become a special type of cultivated soils. The seas were reclaimed and the changed coasts of Holland turned into fertile lands.

Work on the prevention of processes that destroy the soil cover has gained wide scope: forest protection plantations are being created, artificial reservoirs and irrigation systems are being built.

The structure of the land fund of the planet. According to V.P. Maksakovsky, the total area of the land fund of the entire planet is 134 million km 2 (this is the area of the entire land except for the area of Antarctica and Greenland). The land fund has the following structure:

11% (14.5 million km 2) cultivated land (arable land, orchards, plantations, sown meadows);

23% (31 million km2) natural meadows and pastures;

30% (40 million km 2) forests and shrubs;

2% (4.5 million km 2) settlements, industry, transport routes;

34% (44 million km 2) unproductive and unproductive lands (tundra and forest tundra, deserts, glaciers, swamps, ravines, badlands and land waters).

Cultivated lands provide 88% of the food that people need. Grasslands and grazing lands provide 10% of the food consumed by humans.

Cultivated (primarily arable) lands are mainly concentrated in the forest, forest-steppe and steppe regions of our planet.

In the first half of the 20th century half of all cultivated land fell on the black soil of the steppes and forest-steppes, dark prairie soils, gray and brown forest soils, since it is most convenient and productive to cultivate these soils, in our time these soils are plowed up on less than half of the territory occupied by them, however, a further increase in the plowing of these land is constrained by a number of reasons. First, the areas of these soils are heavily populated, industry is concentrated in them, and the territory is crossed by a dense network of transport routes. Secondly, further plowing of meadows, rare remaining forests and artificial plantations, parks and other recreational facilities is environmentally dangerous.

Therefore, it is necessary to search for reserves in the distribution areas of other soil groups. The prospects for the expansion of arable land in the world have been studied by soil scientists from different countries. According to one of these studies, conducted by Russian scientists, taking into account environmental conditions, an increase in agriculture is environmentally acceptable due to the plowing of 8.6 million km 2 of pastures and 3.6 million km 2 of forests, while plowing forest areas is expected mainly in humid tropics and partly in taiga forests, and pastures - in the seasonally humid tropics and subtropics, as well as in humid tropics, semi-deserts and deserts. According to the forecast of these scientists, the largest amount of arable land in the future should be concentrated in the tropical zone, in second place will be the lands of the subtropical zone, while the soils of the subboreal zone (chernozem, chestnut, gray and brown forest soils, dark prairie soils) traditionally considered the main base for agriculture ) will take third place.

The uneven use of different types of soil in agriculture is illustrated by the picture of the agricultural use of the soil cover of the continents. As of the 70s, the soil cover of Western Europe was plowed by 30%, Africa by 14%, on the vast surface of North and South America, arable land accounted for only 3.5% of this territory, Australia and Oceania were plowed a little more than by 4%.

The main problem of the world land fund is the degradation of agricultural lands. Such degradation is understood as the depletion of soil fertility, soil erosion, soil pollution, a decrease in the biological productivity of natural pasture lands, salinization and waterlogging of irrigated areas, alienation of land for the needs of housing, industrial and transport construction.

According to some estimates, humanity has already lost 2 billion hectares of once productive land. Due to erosion alone, which is widespread not only in backward, but also in developed countries, 67 million hectares fall out of agricultural circulation every year. Approximately half of the world's irrigated lands are saline and waterlogged, which also leads to an annual loss of 200300 thousand hectares of land

Destruction of soils as a result of human activity. The natural environment around us is characterized by a close connection of all its constituent parts, carried out due to cyclic processes of metabolism and energy. The soil cover of the Earth (pedosphere) is inextricably linked by these processes with other components of the biosphere. An ill-considered anthropogenic impact on individual natural components inevitably affects the state of the soil cover. Well-known examples of unforeseen consequences of human economic activity are soil destruction as a result of changes in the water regime after deforestation, waterlogging of fertile floodplain lands due to the rise in groundwater levels after the construction of large hydroelectric power plants, etc. Anthropogenic soil pollution creates a serious problem. The uncontrollably growing amount of emissions of industrial and domestic waste into the environment in the second half of the 20th century. reached dangerous levels. Chemical compounds that pollute natural waters, air and soil enter plant and animal organisms through trophic chains, thereby causing a consistent increase in the concentration of toxicants in them. Protection of the biosphere from pollution and more economical and rational use natural resources the global task of our time, on the successful development of which the future of mankind depends. In this regard, the protection of the soil cover, which takes on most of the technogenic pollutants, partially fixes them in the soil mass, partially transforms them and includes them in migration flows, is of particular importance.

The problem of increasing environmental pollution has long acquired planetary significance. In 1972, a special UN conference on the environment was held in Stockholm, at which a program was developed that included recommendations for organizing a global environmental monitoring (control) system.

The soil must be protected from the influence of processes that destroy its valuable properties - structure, content of soil humus, microbial population, and at the same time from the ingress and accumulation of harmful and toxic substances.

Soil erosion. In case of violation of the natural vegetation cover under the influence of wind and precipitation, the destruction of the upper horizons of the soil can occur. This phenomenon is called soil erosion. With erosion, the soil loses small particles and changes its chemical composition. The most important chemical elements - humus, nitrogen, phosphorus, etc. - are removed from eroded soils, the content of these elements in eroded soils can be reduced several times. Erosion can be caused by several reasons.

Wind erosion is caused by wind blowing loose soil cover. The amount of soil blown out in some cases reaches very large sizes 120124 t/ha. Wind erosion develops mainly in areas with destroyed vegetation and insufficient atmospheric moisture.

As a result of partial winding, the soil loses tens of tons of humus and a significant amount of plant nutrients from each hectare, which causes a noticeable decrease in yield. Every year, millions of hectares of land are abandoned due to wind erosion in many countries of Asia, Africa, Central and South America.

The winding of soils depends on wind speed, the mechanical composition of the soil and its structure, the nature of the vegetation, and some other factors. The winding of soils of light mechanical composition begins with a relatively weak wind (speed 34 m/s). Heavy loamy soils are blown by the wind at a speed of about 6 m/s or more. Structured soils are more resistant to erosion than pulverized soils. Erosion-resistant soil is considered to be soil containing more than 60% of aggregates larger than 1 mm in the upper horizon.

To protect soils from wind erosion, obstacles are created for moving air masses in the form of forest strips and wings of shrubs and tall plants.

One of the global consequences of erosion processes that took place both in very ancient times and in our time is the formation of anthropogenic deserts. These include the deserts and semi-deserts of Central and Western Asia and North Africa, which most likely owed their formation to the pastoral tribes that once inhabited these territories. What could not be eaten by countless herds of sheep, camels, horses, was cut down and burned by pastoralists. Unprotected after the destruction of vegetation, the soil was subjected to desertification. In a time very close to us, literally before the eyes of several generations, a similar process of desertification due to ill-conceived sheep breeding covered many parts of Australia.

The total area of man-made deserts by the end of the 1980s exceeded 9 million km 2, which is almost equal to the territory of the United States or China and accounts for 6.7% of the entire land fund of the planet. The process of anthropogenic desertification continues to this day. Another 30 to 40 million km 2 within more than 60 countries are under the threat of desertification. The problem of desertification is referred to the global problems of mankind.

The main causes of anthropogenic desertification are overgrazing, deforestation, as well as excessive and improper exploitation of cultivated lands (monoculture, plowing of virgin lands, cultivation of slopes).

It is possible to stop the process of desertification, and such attempts are being made, primarily within the framework of the UN. Back in 1997 international conference The UN in Nairobi adopted a plan to combat desertification, which primarily concerns developing countries and included 28 recommendations, the implementation of which, according to experts, could at least prevent the expansion of this dangerous process. However, it was only partially implemented for various reasons and, first of all, due to an acute shortage of funds. It was assumed that the implementation of this plan would require 90 billion dollars (4.5 billion over 20 years), but it was not possible to fully find them, so the duration of this project was extended until 2015. And the population in the arid and semi-arid regions of the world, according to UN estimates, is now more than 1.2 billion people.

Water erosion destruction of soil cover not fixed by vegetation under the influence of flowing waters. Atmospheric precipitation is accompanied by a planar washout of small particles from the soil surface, and heavy rains cause severe destruction of the entire soil layer with the formation of gullies and ravines.

This type of erosion occurs when the vegetation cover is destroyed. It is known that herbaceous vegetation retains up to 15-20% of precipitation, and tree crowns even more. especially important role the forest litter plays, which completely neutralizes the impact force of raindrops and sharply reduces the speed of flowing water. The clearing of forests and the destruction of forest litter causes an increase in surface runoff by a factor of 23. The increased surface runoff entails a vigorous washout of the upper part of the soil, which is richest in humus and nutrients, and contributes to the vigorous formation of ravines. favorable conditions For water erosion, both the plowing of vast steppes and prairies and improper tillage create.

Soil washout (planar erosion) is enhanced by the phenomenon of linear erosion erosion of soils and parent rocks as a result of the growth of ravines. In some areas, the ravine network is so developed that it occupies a large part of the territory. The formation of ravines completely destroys the soil, intensifies the processes of surface washout and dismembers arable areas.

The mass of washed soil in the areas of agriculture ranges from 9 t/ha to tens of tons per hectare. The amount of organic matter washed off throughout the year from all over the land of our planet is an impressive figure of about 720 million tons.

Preventive measures for water erosion are the preservation of forest plantations on steep slopes, proper plowing (with the direction of furrows across the slopes), regulation of livestock grazing, strengthening the soil structure through rational agricultural technology. To combat the consequences of water erosion, they use the creation of field-protective forest belts, the installation of various engineering structures to retain surface runoff - dams, dams in ravines, water-retaining shafts and ditches.

Erosion is one of the most intensive processes of soil cover destruction. The most negative side Erosion of the soil cover is not in the impact on the loss of the crop of a given year, but in the destruction of the structure of the soil profile and the loss of its important components, the restoration of which takes hundreds of years.

Soil salinization. In areas with insufficient atmospheric moisture, crop yields are constrained by an insufficient amount of moisture entering the soil. To make up for its deficiency, artificial irrigation has been used since ancient times. Worldwide, over 260 million hectares of soils are irrigated.

However, improper irrigation leads to the accumulation of salts in irrigated soils. The main causes of anthropogenic soil salinization are non-drainage irrigation and uncontrolled water supply. As a result, the water table rises and when the water table reaches a critical depth, vigorous salt accumulation begins due to the evaporation of salt-containing water rising to the soil surface. This is facilitated by irrigation with water with high mineralization.

As a result of anthropogenic salinization, about 200300 thousand hectares of high-value irrigated lands are lost every year around the world. To protect against anthropogenic salinization, drainage devices are being created, which should ensure the location of the groundwater level at a depth of at least 2.53 m, and a system of canals with waterproofing to prevent water filtration. In case of accumulation of water-soluble salts, it is recommended to flush the soil with a drainage system to remove salts from the root layer of the soil. Soil protection from soda salinization includes soil gypsuming, the use of calcium-containing mineral fertilizers, and the introduction of perennial grasses into crop rotation.

For a warning negative consequences irrigation requires constant monitoring of the water-salt regime on irrigated lands.

Reclamation of soils disturbed by industry and construction. Human economic activity is accompanied by the destruction of the soil. The area of soil cover is steadily decreasing due to the construction of new enterprises and cities, the laying of roads and high-voltage power lines, the flooding of agricultural land during the construction of hydroelectric power stations, and the development of the mining industry. Thus, huge quarries with waste rock heaps, high waste heaps near mines are an integral part of the landscape of mining areas.

Many countries are recultivating (restoring) the destroyed areas of the soil cover. Reclamation is not just backfilling of mine workings, but the creation of conditions for the fastest formation of soil cover. In the process of reclamation, the formation of soils, the creation of their fertility. To do this, a humus layer is applied to the dump soils, however, if the dumps contain toxic substances, then it is first covered with a layer of non-toxic rock (for example, loess) on which a humus layer is already applied.

In some countries, exotic architectural and landscape complexes are created on dumps and quarries. Parks are laid out on dumps and waste heaps, and artificial lakes with fish and bird colonies are arranged in quarries. For example, in the south of the Rhine lignite basin (FRG), dumps have been dumped since the end of the last century with the expectation of creating artificial hills, later covered with forest vegetation.

Chemicalization of agriculture. The successes of agriculture achieved as a result of the introduction of advances in chemistry are well known. High yields are obtained through the use of mineral fertilizers, the preservation of grown products is achieved with the help of pesticides - pesticides created to control weeds and pests. However, all these chemicals must be used very carefully and strictly observe the quantitative norms of introduced chemical elements developed by scientists.

1. Application of mineral fertilizers

When wild plants die, they return the chemical elements absorbed by them to the soil, thereby maintaining the biological cycle of substances. But this does not happen with cultivated vegetation. The mass of cultivated vegetation only partially returns to the soil (about one third). A person artificially violates the balanced biological cycle, taking out the crop, and with it the chemical elements absorbed from the soil. First of all, this refers to the “fertility triad”: nitrogen, phosphorus and potassium. But humanity has found a way out of this situation: to make up for the loss of plant nutrients and increase productivity, these elements are introduced into the soil in the form of mineral fertilizers.

Problem nitrogen fertilizers . If the amount of nitrogen introduced into the soil exceeds the needs of plants, then excess amounts of nitrates partly enter plants, and partly are removed by soil water, which causes an increase in nitrates in surface water, as well as a number of other negative consequences. With an excess of nitrogen, there is an increase in nitrates in agricultural products. Entering the human body, nitrates can be partially transformed into nitrites. , which cause a serious illness (methemoglobinemia), associated with difficulty transporting oxygen through the circulatory system.

The use of nitrogen fertilizers should be carried out with strict consideration of the need for nitrogen for the crop, the dynamics of its consumption by this crop and the composition of the soil. A well-thought-out system of soil protection from excess nitrogen compounds is needed. This is especially important due to the fact that modern cities and large livestock enterprises are sources of nitrogen pollution of soils and waters.

Techniques for using biological sources of this element are being developed. These are the nitrogen-fixing communities of higher plants and microorganisms. Sowing legumes (alfalfa, clover, etc.) is accompanied by nitrogen fixation up to 300 kg/ha.

Phosphate fertilizer problem . With the harvest, about two-thirds of the phosphorus captured by crops from the soil is removed. These losses are also restored by applying mineral fertilizers to the soil.

Modern intensive agriculture is accompanied by pollution of surface waters with soluble compounds of phosphorus and nitrogen, which accumulate in the final runoff basins and cause the rapid growth of algae and microorganisms in these reservoirs. This phenomenon is called eutrophication. reservoirs. In such reservoirs, oxygen is quickly consumed for the respiration of algae and for the oxidation of their abundant residues. Soon, a situation of oxygen deficiency is created, due to which fish and other aquatic animals die, their decomposition begins with the formation of hydrogen sulfide, ammonia and their derivatives. Eutrophication has affected many lakes, including the Great Lakes of North America.

The problem of potash fertilizers. When applying high doses of potash fertilizers, no adverse effect was found, but due to the fact that a significant part of the fertilizers is represented by chlorides, the effect of chloride ions, which negatively affects the condition of the soil, often affects.

The organization of soil protection with the widespread use of mineral fertilizers should be aimed at balancing the masses of fertilizers applied with the crop, taking into account specific landscape conditions and soil composition. The application of fertilizers should be as close as possible to those stages of plant development when they need a massive supply of the corresponding chemical elements. The main task of protective measures should be aimed at preventing the removal of fertilizers with surface and underground water runoff and at preventing the ingress of excess amounts of introduced elements into agricultural products.

The problem of pesticides (pesticides). According to the FAO, annual losses worldwide from weeds and pests account for 34% of the potential production and are estimated at $75 billion. negative consequences. Destroying pests, they destroy complex ecological systems and contribute to the death of many animals. Some pesticides gradually accumulate along the trophic chains and, entering the human body with food, can cause dangerous diseases. Some biocides affect the genetic apparatus more than radiation.

Once in the soil, pesticides dissolve in soil moisture and are transported down the profile with it. The duration of pesticides in the soil depends on their composition. Persistent compounds persist for up to 10 years or more.

Migrating with natural waters and carried by the wind, persistent pesticides spread over long distances. It is known that negligible traces of pesticides were found in atmospheric precipitation in the vast oceans, on the surface of the ice sheets of Greenland and Antarctica. In 1972, more DDT fell on the territory of Sweden with precipitation than was produced in this country.

The protection of soils from pollution by pesticides involves the creation of possibly less toxic and less persistent compounds. Techniques are being developed to reduce doses without reducing their effectiveness. It is very important to reduce airborne spraying at the expense of ground spraying, as well as the use of strictly selective spraying.

Despite the measures taken, when the fields are treated with pesticides, only an insignificant part of them reaches the target. Most of it accumulates in the soil cover and natural waters. An important task is to accelerate the decomposition of pesticides, their breakdown into non-toxic components. It has been established that many pesticides decompose under the influence of ultraviolet radiation, some toxic compounds are destroyed as a result of hydrolysis, but pesticides are most actively decomposed by microorganisms.

Now many countries, including Russia, control environmental pollution with pesticides. For pesticides, norms of maximum permissible concentrations in the soil are established, which are hundredths and tenths of mg/kg of soil.

Industrial and domestic emissions into the environment. Over the past two centuries, the production activity of mankind has increased dramatically. Various types of mineral raw materials are increasingly involved in the sphere of industrial use. Now people spend 3.5 4.03 thousand km 3 of water per year for various needs, i.e. about 10% of the total flow of all rivers in the world. At the same time, tens of millions of tons of domestic, industrial and agricultural waste enter surface waters, and hundreds of millions of tons of gases and dust are emitted into the atmosphere. Production activity man has become a global geochemical factor.

Such intense human impact on the environment is naturally reflected in the soil cover of the planet. Man-made emissions into the atmosphere are also dangerous. The solids of these emissions (particles of 10 microns and larger) settle close to the sources of pollution, smaller particles in the composition of gases are transported over long distances.

Pollution with sulfur compounds. Sulfur is released during the combustion of mineral fuels (coal, oil, peat). Significant amount oxidized sulfur is released into the atmosphere during metallurgical processes, cement production, etc.

The greatest harm is caused by the intake of sulfur in the form

SO 2, sulfurous and sulfuric acid. Sulfur oxide, penetrating through the stomata of the green organs of plants, causes a decrease in the photosynthetic activity of plants and a decrease in their productivity. Sulfurous and sulfuric acids, falling out with rainwater, affect vegetation. Presence SO 2 in the amount of 3 mg/l causes a decrease in the pH of rainwater to 4 and the formation of "acid rain". Fortunately, the lifetime of these compounds in the atmosphere is measured from several hours to 6 days, but during this time they can be transported with air masses for tens and hundreds of kilometers from pollution sources and fall out in the form of "acid rain".

Acidic rainwater increases the acidity of soils, inhibits the activity of soil microflora, increases the removal of plant nutrients from the soil, pollutes water bodies, and affects woody vegetation. To some extent, the effect of acid precipitation can be neutralized by liming the soil.

Heavy metal pollution. No less dangerous for the soil cover are pollutants that fall close to the source of pollution. This is how pollution with heavy metals and arsenic manifests itself, which form technogenic geochemical anomalies, i.e. areas of increased concentration of metals in the soil cover and vegetation.

Metallurgical enterprises annually throw hundreds of thousands of tons of copper, zinc, cobalt, tens of thousands of tons of lead, mercury, nickel onto the earth's surface. Technogenic dispersion of metals (of these and others) also occurs in other production processes.

Man-made anomalies around manufacturing enterprises and industrial centers have a length of several kilometers to 30-40 km, depending on the production capacity. The content of metals in soil and vegetation rather quickly decreases from the pollution source to the periphery. Two zones can be distinguished within the anomaly. The first, directly adjacent to the source of pollution, is characterized by a strong destruction of the soil cover, the destruction of vegetation and wildlife. This area is very high concentration pollutant metals. In the second, larger zone, the soils completely retain their structure, but microbiological activity is inhibited in them. In soils contaminated with heavy metals, an increase in the metal content from bottom to top along the soil profile and its highest content in the outermost part of the profile are clearly expressed.

Main source of pollution lead road transport. Most of the emissions (80-90%) are deposited along highways on the surface of soils and vegetation. Thus, roadside geochemical anomalies of lead are formed with a width (depending on the traffic intensity) from several tens of meters to 300-400 m and a height of up to 6 m.

Heavy metals, coming from the soil into plants and then into the organisms of animals and humans, have the ability to gradually accumulate. The most toxic mercury, cadmium, lead, arsenic, poisoning them causes severe consequences. Zinc and copper are less toxic, but their contamination of soils suppresses microbiological activity and reduces biological productivity.

The limited distribution of pollutant metals in the biosphere is largely due to the soil. Most of the easily mobile water-soluble metal compounds, entering the soil, are strongly associated with organic matter and finely dispersed clay minerals. The fixation of pollutant metals in the soil is so strong that in the soils of the old metallurgical regions of the Scandinavian countries, where ore smelting stopped about 100 years ago, a high content of heavy metals and arsenic has remained to this day. Consequently, the soil cover plays the role of a global geochemical screen that traps a significant part of pollutant elements.

However, the protective ability of soils has its limits, so the protection of soils from heavy metal pollution is an urgent task. To reduce the release of metal emissions into the atmosphere, a gradual transition of production to closed technological cycles is necessary, as well as the mandatory use of treatment facilities. see also SOIL TYPES ; SOIL MORPHOLOGY.

Natalia Novoselova

LITERATURE Soils of the USSR. M., Thought, 1979
Glazovskaya M.A., Gennadiev A.N. , Moscow, Moscow State University, 1995
Dobrovolsky V.V. Geography of soils with the basics of soil science. M., Vlados, 2001
Zavarzin G.A. Lectures on Natural History Microbiology. M., Nauka, 2003

For several years now I have been influencing the quality of the soil on my personal plot. I try to increase the yield by adding manure, hay, grass clippings, and some natural fertilizers to the soil. The result is not long in coming: for 4 months a year our family eats fresh tomatoes, cucumbers and herbs every day, and we also pick cherries and apricots from the trees. Consider the impact of man on the soil on a larger scale.

Examples of the positive human impact on soil formation

fertile soil humanity needs complete food supply. Therefore, people are making efforts to preserve this valuable resource. We list the activities that positively affect the soil:

Agriculture. With its reasonable management, agronomists annually alternate crops in the same field, apply fertilizers, and carry out competent plowing. All this leads to the formation of quality soil;
environmental protection. Ecologists recommend to carry out
artificial planting of forest belts to save the soil of adjacent fields from erosion.

Now much attention is paid to the condition of the soil, because, in connection with the growth of the population, the issue of a shortage of all natural resources has become acute.

Examples of the negative human impact on soil formation

Unfortunately, more items can be listed here, because many types contemporary activities disrupt the balance of many processes, including soil formation:

deforestation contributes to the weathering of the soil and the formation of the desert. This is especially evident in South America, where local residents have already destroyed large areas of forest in order to plow up new lands;
industry is a source of soil polluting waste, which
not only reduce its fertility, but can also get into the crop;
construction. During the construction of any object, the area of fertile land
decreases. Big cities are an important attribute of modernity, but they encase vast areas in asphalt and concrete;
cars- Gasoline waste also makes the soil poisonous.