The importance of soil in the life of organisms. Importance of soil for human life. Importance of soil in the water cycle

It is an indispensable element of the earth's surface, thanks to which the existence of plant and animal organisms (as well as microorganisms) becomes possible.

The interaction here is twofold: all living things would not exist without soil, but the soil itself is the result of the vital activity of these organisms. The soil is one of the planetary shells, which is commonly called the pedosphere.

Soil and cycling. Thanks to a specific mixture of soil elements, water, air and organic components, the processes of processing, decomposition and transformation of many chemical compounds take place.

Thanks to this, it becomes possible to provide nutrition primarily for plants, and indirectly for animals and humans.

What is the importance of soil in nature?

The value of soil in nature can be divided depending on its functions, the main of which are as follows:

The concentration of energy reserves due to the provision of vital processes of plants and the implementation of photosynthesis by them (and, consequently, the formation of many minerals).
Creation of interaction between small and large cycles of substances - biological and geological.
Implementation of the regulation of the main processes in the biosphere - the regulation of the productivity of living organisms and the density of their population on the surface of the planet.
Participation in the interconnected process of regulation of atmospheric and hydrospheric compositions.
Ensuring the normal processes of vital activity of terrestrial organisms.
Ecological role - participation in the functionality of the ecosystem and how component biogeocenosis.
important role in complex mechanisms functioning and regulation of the atmosphere, hydrosphere, lithosphere, biosphere and ethnosphere.

The importance of soil in human life

By its very existence, the soil provides an opportunity for life to man and other living organisms. Soil and man are inextricably linked with each other. No wonder the first efficient technologies human civilization were agriculture and animal husbandry - that is, in fact, the maximum ways to use land resources.

energy function

The soil creates conditions for the life of plants that convert solar energy by photosynthesis into organic. Gradually, plants and other organic residues turn into coal, oil, gas, peat, thereby creating giant reservoirs of energy for human civilization.

Soil is an active participant in the circulation of organic and geological components. Such important structural elements as nitrogen, oxygen and carbon undergo conversion processes with the help of the soil. Through complex transformations, these chemical elements are both released into the hydrosphere and atmosphere, and become a source of organic synthesis for plants.

It is very important that the composition of the soil includes the mineral elements necessary for the normal functioning of the human body.

Natural regulation of populations

The accumulation of plant and animal organisms (as well as humans) always occurs in those areas of the planet where the soil is most fertile and the climate is conducive to life. Conversely, soils with low fertility reduce the possibilities for the existence of flora and fauna on them, thereby regulating the number of certain species and populations.

IN social relations The role of the soil is manifested in the fact that high-yielding lands become the cause of territorial conflicts between countries and peoples.

Soil as a means of production

Undoubtedly, the soil is a valuable means for the production of agricultural and livestock products. One should always take into account the importance of maintaining the ecological state of the soil when carrying out various agrotechnical works and organizing types of production associated with the release of toxins and Wastewater into the environment.

The future of life on the planet directly depends on the condition of the soil. In addition, soil is needed to create dwellings and roads.

The protective function of the soil

The soil not only gives life, but also neutralizes substances dangerous to human and animal life. These are harmful chemical compounds, and radioactive substances, and dangerous bacterial and viral pathogens. All these components accumulate in the soil and are gradually utilized.

However, the buffer margin of soil strength is not unlimited, and if it is constantly exceeded, it will cease to cope with its tread functions.

We hear the words "the land is the breadwinner" so often that we hardly attach any importance to them. But it would be more correct to say that trees and grass grow, forests rustle and wheat sways in the field only due to the fact that we have land, or rather soil. Soil formation began with the appearance of the first living beings on Earth, so it is to them that we owe life, and not only genetically. "Since ancient times, people have known that the world around them has an amazing property, which was called fertility. The most noticeable, most everyday close and understandable to people, this property was manifested by the soil, which owes its existence and development to the modern flora and fauna. It is necessary condition for plant, animal and human life. Cultivating crops, people noticed that the crop grown from the seeds of the same plant is not the same on different plots of land.

The soil also plays an important role in the natural habitat of man. Soil, being classified as a non-renewable natural resource, is the main means of agricultural production. International declarations and agreements on the problems of nature management ("World Strategy for Conservation of Nature", "World Soil Charter", "Fundamentals of World Soil Policy") affirm the importance of soil as a common property of mankind, which should be rationally used and protected by all people of the Earth.

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 problems. 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 most important importance of soils is the accumulation of organic matter, various chemical elements, as well as energy. The soil cover functions as a biological absorber, destroyer and neutralizer of various contaminants. In addition, the soil 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 km2 or 86.5% of the land area. Arable land and perennial plantations as part of agricultural land occupy about 15 million km2 (10% of land), hayfields and pastures - 37.4 million km2 (25% of land). The general arable suitability of lands is estimated by various researchers in different ways: from 25 to 32 million km2.

If this link of the biosphere is destroyed, then the existing functioning of the biosphere will be irreversibly disrupted. Modern soil cover has been formed over thousands of years, in conditions that have now completely changed. Hence, the importance of the correct and efficient use and conservation of soil resources immeasurably increases.

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 problems: the preservation of the evolution of living, hereditary substances (the gene pool of flora and fauna), the preservation of the purity and productivity of natural environments (atmosphere, hydrosphere, soil, forests, etc.). ), ecological regulation of the anthropogenic pressure on natural ecosystems within their buffer capacity, the preservation of the ozone layer, trophic chains in nature, the biocirculation 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 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 current state and changes under the influence of anthropogenic activity.

The soil

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.

Soil value

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 food resources for the population of the planet. The land area of the world is 129 million km 2 or 86.5% of the land area. Arable land and perennial plantings 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 land 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 in late XIX 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 structure

Soil is a special natural formation that has a number of properties inherent in living and inanimate nature. The soil is the environment where most of the elements of the biosphere interact: water, air, living organisms. 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), 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 with 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 B is the parent rock.

The surface horizon consists of the remains of vegetation, which form the basis of humus, the excess or deficiency of which determines the fertility of the soil.

Humus -- organic matter that is most resistant to decomposition and therefore persists after the main decomposition process has 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 -- subarable. The main functions of humus "are reduced to a series of complex metabolic processes, in which not only nitrogen, oxygen, carbon and water participate, 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 maternal breed.

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

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

Soil formation has been taking place on Earth since the beginning of life and depends on many factors:

The substrate on which soils form. depends on the nature of the parent breeds physical properties soils (porosity, water-holding capacity, looseness, etc.). They determine the water and thermal regime, the intensity of mixing of substances, the mineralogical and chemical composition, the initial content of nutrients, and the type of soil.

Vegetation - green plants (the main creators of primary organic matter). Absorbing carbon dioxide from the atmosphere, water and minerals from the soil, using light energy, they create organic compounds suitable for animal nutrition.

With the help of animals, bacteria, physical and chemical influences, organic matter decomposes, turning into soil humus. Ash substances fill the mineral part of the soil. Undecomposed plant material creates favorable conditions for the action of soil fauna and microorganisms (stable gas exchange, thermal regime, humidity).

Animal organisms that perform the function of converting organic matter into the soil. Saprophages (earthworms, etc.), feeding on dead organic matter, affect the humus content, the thickness of this horizon and the structure of the soil. Of the terrestrial fauna, soil formation is most intensively influenced by all types of rodents and herbivores.

Microorganisms (bacteria, unicellular algae, viruses) decomposing complex organic and mineral substances into simpler ones, which can later be used by the microorganisms themselves and higher plants.

Some groups of microorganisms are involved in the transformation of carbohydrates and fats, others - nitrogenous compounds. Bacteria that absorb molecular nitrogen from the air are called nitrogen-fixing. Thanks to their activities, atmospheric nitrogen can be used (in the form of nitrates) by other living organisms. Soil microorganisms take part in the destruction of toxic metabolic products of higher plants, animals and microorganisms themselves in the synthesis of vitamins necessary for plants and soil animals.

Climate affecting thermal and water regimes soil, and hence on the biological and physico-chemical soil processes.

A relief that redistributes heat and moisture on the earth's surface.

Human economic activity 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, reclamation is carried out.

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

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

Soil erosion, destruction of soils under the influence of wind, water, machinery and irrigation. The most dangerous is water erosion - the washing away of the soil by melt, rain and storm water. Water erosion is noted at a steepness of already 1-2 °. Water erosion contributes to the destruction of forests, plowing on the slope.

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

Irrigation erosion develops as a result of violation of irrigation rules 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. 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% over the past 20 years in the Russian Federation, and the annual loss is 81.4 million tons. The earth today can feed 15 billion people . Careful and competent handling of land today has become the most urgent problem.

It follows from the foregoing that the soil includes mineral particles, detritus, many living organisms, i.e. 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. From what has been said, it follows that the soil is less mobile compared to other abiotic components of the biosphere.

Human economic activity is currently becoming the dominant factor in the destruction of soils, the decrease and increase in their fertility.

We hear the words "the land is the breadwinner" so often that we hardly attach any importance to them. But it would be more correct to say that trees and grass grow, forests rustle and wheat sways in the field only due to the fact that we have land, or rather soil. Soil formation began with the appearance of the first living beings on Earth, so it is to them that we owe life, and not only genetically. "Since ancient times, people have known that the world around them has an amazing property, which was called fertility. The most noticeable, most everyday, close and understandable to people, this property was manifested by the soil, which owes its existence and development to the modern flora and fauna. It is a necessary condition for the life of plants, animals, humans.Cultivating agricultural crops, people noticed that the crop grown from the seeds of the same plant is not the same on different land plots.

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 problems. 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 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. In addition, the soil is the most important natural formation.

The soil cover of the Earth seems to us ordinary and eternally existing in nature. However, it is not. Nature has been creating soil for 4.5 billion years! The basis for the formation of the soil was the weathering products of rocks. Weathering is a complex process, the result of the combined action of many physical, chemical and biological factors. Video 37.

Conventionally, this is reflected in the formula:Rocks + Sun + air + water + living organisms = soil.

The process of soil formation never stops, of course, it continues today, but very slowly. The soil is in a constant process of development - formation or destruction. The duration of the process of formation of the soil cover of the Earth is due to many factors. It takes thousands of years for soil to form. At the same time, irrational nature management, which is detrimental to the soil, can destroy it in just a few years.

Do you think soil should be classified as a renewable or non-renewable natural resource? Is it possible to give an unambiguous answer to this question?

Thanks to the soil cover of the Earth, the life of plants, animals and humans is provided. Soil is the most important component of all terrestrial ecological systems of the Earth and is itself a unique ecosystem (see topics 2 and 3 for more details). It connects living organisms with the lithosphere, atmosphere and hydrosphere. The soil is the object of study of a separate science - soil science. The founder of soil science is an outstanding Russian scientist Vasily Vasilievich Dokuchaev. Petersburg is the Central Museum of Soil Science. V.V. Dokuchaev, which is one of the world's largest museums of soil and ecological profile. In the museum you can get answers to questions - What is soil? How is it formed? What grows in this soil? Who lives in this soil? The museum is the custodian of the richest collection of soils from various natural zones of the world.

Currently, scientists distinguish about a hundred types of soils. Why do they exist different types soil?

The variety of soils is connected, of course, with the variety of conditions in which they were formed. Of particular importance are the climate and the properties of the rocks from which the soil was formed.

Look at the picture and compare chernozem, soddy-podzolic and tundra podzolic soils.

Do you know what soil types are typical for your area? The soil has several layers connected to each other. Video 38. Among them, there are bedrock, which is subject to weathering when it comes to the surface, and parent rock, from which the topsoil is formed. The underlying layer is called the subsoil.

The unique property of the soil is fertility. It is what ensures the existence of life on Earth. Soil fertility is due to the content of humic substances (humus) in it. Humus is an accumulation of organic substances that were formed during the decay of plant and other living things. It gives the soil a black color and ensures the growth and development of plants (i.e. life on Earth). The more humus in the soil, the more fertile it is. Most of the humus is found in chernozem soils. Video 39.

What is soil made of?

Approximately 50% of the space in the soil is occupied by air, filling the gaps between solid particles. About 45% of the mass of the soil falls on the share of minerals, about 5% - on the share of organic substances. However, these data on the composition of the soil do not give a real picture of it.

We are accustomed to thinking that the soil is sparsely populated, that the bulk of living organisms are on its surface. But that's not the case at all! For many animals it is a habitat. Everyone knows that earthworms, insect larvae, and insects themselves live in the soil. The soil serves as a nesting and dwelling place for many birds and other animals. Calculations of scientists show that the mass of living things in the soil is? masses of living inhabitants of forests and more? masses of living steppe vegetation.

It has been established that the smaller the size of organisms, the greater their number in the soil. So, in 1 m 3 of soil there are several tens of millions of worms and insects. And 1 gram of soil contains more than a million of the simplest microorganisms. In general, scientists estimate the number of soil microorganisms on Earth at approximately one billion tons!However, the significance of living organisms in soil processes is determined not by their mass, but by the enormous work that they perform. Video 40.

We do not notice the work of soil bacteria, which continuously process the dying parts of plants and other organisms. But if it stopped, the surface of the Earth would be littered with these remnants. It is hard to imagine what would happen to our beautiful Planet in a hundred years! And earthworms, as you know, eating, swallow the soil. If about 140 thousand earthworms live in one hectare of soil, then their mass is 500 kg! And this means that in one year they pass through their body about ten tons of soil mass!

What is the biospheric function of the soil?

It is important to understand that to characterize the soil, it is not enough to know its composition. Scientific knowledge about the soil is associated with the understanding that it is a complex natural body with a certain structure (structure). Let's remember: Soil is not a mechanical mixture of various substances. Soil is a complex system of interaction of mineral, organic substances and living organisms.

Thanks to their interaction, the soil performs its biospheric functions. But, we repeat, it is provided not only by the composition, but also by the structure of the soil.

Soil is made up of very small particles. Microscopic organisms live in a film of water enveloping soil particles. Larger ones settle between soil particles, as in caves. Both those and others make up a single formation with the soil. Those that live on the surface of the particles need air, and those that are inside the particles are able to live without air.

Nutrition, respiration and all other life processes of living organisms lead to many changes in the composition of the soil. At the same time, they involve in these processes substances contained in the air and dissolved in water, and they themselves release new substances formed in the course of their vital activity.

Thus, the soil performs its biospheric function as the final link that ensures the creation of the entire biomass of the Planet.

Soil destruction can occur both as a result of natural processes and under the influence of irrational human actions.

Destruction of the soil cover at the site of logging

Such natural processes, as the onset of glaciers, volcanic eruption, the formation of mountains, earthquakes, hurricanes, tornadoes or floods, cannot but affect the state of the earth's crust and the processes of soil formation. But natural soil erosion (destruction and demolition of the upper most fertile layers as a result of the action of water and wind) is a slow continuous process, at the same time as a new soil layer is formed. Unlike natural, anthropogenic soil erosion is caused by human intervention in the natural environment for economic purposes. Irrational use fields and pastures, deforestation, drainage of reservoirs and the like - all this can destroy soil fertility in a very short time.

For example, the first settlers in America exploited the land so mercilessly that in 100 years they destroyed 20% of arable land. The soil is also destroyed due to waterlogging, desertification.

Bitter evidence of man's reckless exploitation of nature is the deserts of North Africa, the Baltic dunes, and eroded spaces in Australia, Pakistan, India and Canada. Only in the European part of our country there are up to 2 million ravines, which were formed mainly as a result of plowing the land. Every year, land loses a layer of fertile soil, the creation of which nature has spent thousands of years. Soil scientists call erosion a real tragedy.

Scientists believe that in order to maintain the ecological sustainability of the territory in each natural zone, a certain ratio of arable lands, pastures and forests must be observed. So, for example, in the forest-steppe, according to the research of V.V. Dokuchaev, forests should be 10-18%. Now, due to excessive plowing, there are much fewer of them left.

According to modern data, mankind has already lost about 2 billion hectares of once fertile lands during the historical period, turning them into anthropogenic deserts. This is more than the area of all modern arable land in the world, which is 1.5 billion hectares. At the end of the 20th century, it became obvious that soil degradation has become rampant and is one of the main threats to the global environmental crisis. This is especially worrying when you consider that, according to the latest estimates, there are more than one billion hungry people in the world, that is, one in six people on the planet. This means that more people are now suffering from hunger and malnutrition than at any time in the history of mankind, while the fertility of the soil and the area suitable for Agriculture lands are shrinking.

Do we ever think about what soil means in our lives? Perhaps very rarely. It seems to us that since the soil is not a flower, not an insect, not a beast, what can happen to it? So it will always lie under your feet. And at the same time, the world-famous ecologist Jean Pierre Dorsta said: "The soil is our most precious capital. The life and well-being of the entire complex of terrestrial biocenoses, natural and artificial, ultimately depends on a thin layer that forms the topmost cover of the Earth."

By underestimating the role of this greatest natural wealth, mankind endangers its very existence.

The protection of the soil from its destruction, the fight against a decrease in its fertility is the most important ecological problem requiring urgent attention of the world community.