What layers of earth are there? The Earth's crust is the upper solid shell of the Earth. Layers of the earth
Origin of the Earth
Modern hypotheses of the formation of the Earth and other planets of the solar system are based on those put forward in the 78th century. I. Kant (Germany) and, independently of him, P. Laplace (France) the concept of the formation of planets from dusty matter and gas nebula. In CC c. this concept was developed by O.Yu. Schmidt (USSR), K. Weizsäcker (Germany), F. Foyle (England), A. Cameron (USA) and E. Schatzmann (France).
You can also mix special garden soil under the excavation. Any existing stones should also be removed. If the existing soil is too poor quality, you can also apply additional turf soil mixture. This soil consists of potting soil, silica sand and compost - an ideal mixture that allows plant life to grow quickly. For very loamy soils, it is recommended to apply a layer of high quartz soil. The top layer of soil should be at least 5-10 cm - the higher this layer, the more beautiful your lawn will be.
Kant and Laplace drew attention to the fact that the Sun is hot, and the Earth is cold and much smaller in size than the Sun. At the same time, the Earth is just one of the planets. All planets revolve in circles, in the same direction and in almost the same plane. These constitute the main distinguishing features of the solar system that must be explained first.
Then the surface must be leveled. Carefully level out any unevenness in the floor to give the turf a good overall picture. Additionally, the surface should be properly watered before applying grass tracks to prevent the roller turf from drying out underneath.
It goes without saying that a living product like turf requires regular maintenance. Not only is good underground preparation important, but also daily or weekly assistance until the turf plants have completed their establishment. Provide adequate irrigation every day - ideal in cooler morning temperatures. During the hot afternoon and daytime hours, very ugly brown spots on the peat can otherwise occur. Regular fertilization after laying ensures uniform growth and a uniform and rich dark green color.
Kant and Laplace argued that everything in nature is constantly changing and developing. Both the Earth and the Sun were not previously what they are now, and the substance that constituted them existed in a completely different form.
Laplace substantiated his hypothesis more convincingly. He believed that once there was no solar system, but there was a primary rarefied and hot gas nebula with a compaction in the center. It rotated slowly, and its dimensions were larger than the diameter of the planet most distant from the Sun now.
For optimal care, mow your turf at least once a week and then remove clippings. This stimulates growth and also provides a full appearance. Avoid switching to turf in the first two weeks after installation unless absolutely necessary. However, there is nothing wrong with celebrating cautiously. Once the rooting phase is complete, the peat can finally be used like any other peat. Over time and stress, your lawn can develop joints or stains. Adequate ventilation is very important.
Especially in the fall, a lot of leaves can accumulate on your lawn. It also inhibits light absorption and favors living conditions for fungi, felt and other unwanted side effects. Only ordinary Abharken helps here. Equip your turf even for the upcoming winter winters, not only mow it regularly before the first frost, but also fertilize it in the fall.
The gravitational attraction of the nebula particles to each other led to the compression of the nebula and a decrease in its size. According to the law of conservation of angular momentum, when a rotating body is compressed, its rotation speed increases. Therefore, when the nebula rotated, a large number of particles at its equator (which rotated faster than those at the poles) came off, or, more precisely, peeled off from it. A rotating ring appeared around the nebula. At the same time, the nebula, spherical at first, was flattened at the poles due to centrifugal force and became like a lens.
How often should you water your turf?
Avoid exposing your lawn to freezing weather as this can cause the grasses to tear apart and open the door to lawn disease. Turf should be watered from the first day, except, of course, on rainy days. Irrigation is temperature dependent and should be done once or twice a day, with approximately 5-8 liters per square meter. This corresponds to soil moisture of three to five centimeters. If you lift the sod a little, the sod should be completely damp, as well as underneath it. The motto “A lot helps a lot” is, of course, inappropriate here.
All the time contracting and accelerating its rotation, the nebula gradually peeled off ring after ring, which rotated in the same direction and in the same plane. The gas rings had density inhomogeneities. The greatest concentration in each of the rings gradually attracted the rest of the substance of the ring. So each ring turned into one large ball of gas, rotating around its axis. After this, the same thing happened to him as with the huge primary nebula: he turned into a relatively small ball, surrounded by rings, again condensing into small bodies. The latter, having cooled, became satellites of large gas balls that revolved around the Sun and, after solidification, turned into planets. Nai most of nebulae concentrated in the center; it has not cooled down yet and has become the Sun.
Puddles are taboo, and shit should be easily accessible. Make sure the irrigation system is watered evenly, as individual networks may otherwise form joints and then no longer grow together. The same goes for light or brown dry spots. If you want to be safe, you can rely on an automatic intercom with sensor. About 10-14 days after laying the lawn, you will notice by slightly lifting the edges that the roots of the roller lawn have already grown and are beginning to grow along with the soil.
Laplace's hypothesis was scientific because it was based on the laws of nature known from experience. However, after Laplace, new phenomena were discovered in solar system, which his theory could not explain. For example, it turned out that the planet Uranus rotates around its axis in a different direction than the other planets. The properties of gases and the peculiarities of the movement of planets and their satellites were better studied. These phenomena also did not agree with Laplace's hypothesis and it had to be abandoned.
At this point, and during cool, wet weather, you can slowly reduce the irrigation. If the turf is after. 6 weeks, irrigation can be reduced to once or twice a week. In conditions of high temperature and drought it is required more water. Here, 15 to 20 liters are required per casting.
The same applies to peat: quality has its price. Is it a play lawn that resists normal garden stress? This question needs to be clarified in advance. For the price of a square meter of roller peat, which ranges from €3.50 to €6.00, you must take into account the costs of fertilization and delivery, as well as the processing of the substrate. The workload is important here: extensive dredging, application of a layer of soil or humus, subsequent compaction using specially designed equipment and, of course, the laying itself.
The famous Soviet scientist academician O.Yu. Schmidt proposed a hypothesis, in the development of which astronomers, geophysicists, geologists and other scientists took part, and according to which the Earth and other planets were never hot gas bodies like the Sun and stars, but should have been formed from cold particles of matter. These particles initially moved randomly. Then their orbits became circular and located approximately in the same plane. In this case, the direction of rotation of the particles in any particular direction began to prevail over time, and eventually all the particles began to rotate in the same direction.
However, garden owners can save a lot of money if they do the collection and installation of roller sod themselves. The same applies to subsoil preparation and planning. But don't skimp on the wrong corner, because with very large area, it is advisable to leave extensive work to a specialist specialist company. In terms of price, turf is installed higher than even lawns that have been seeded, but in a very short time you will have a lawn that you can use normally if treated correctly.
As a result of the collision of particles during the initial random motion, the energy of their movement was partially converted into heat and dissipated into space. Calculations showed that as a result of these processes, the spherical cloud gradually flattened and finally became shaped like a pancake. Further, gravitational interaction led to the growth of larger particles by trapping small particles. Thus, most of the dust grains gathered into several giant lumps of matter, which became planets.
How long does it take for turf to grow?
Rolling sod takes less time to form a continuous peat than conventional seed grass. Therefore, take care good care and watering so that it is completely rooted in about six weeks and is one unit. The herbivore is a monocotyledonous herbaceous plant that is capable of forming a flat plant cover and reproducing from root shoots. Thanks to this circumstance, it is possible to lay turf as turf. In this way, individual plants grow together, multiply and thus close the joints between the paths.
According to estimates obtained by Schmidt, the formation of the Solar System took 6-7 billion years, which is in order of magnitude consistent with the data obtained as a result of isotopic analysis.
According to Schmidt's hypothesis, the Earth was never fiery-liquid, and the heating of the inner region of the Earth occurred as a result of nuclear reactions of the decay of heavy elements that were part of the original substance.
In addition, turf also has a soil protecting effect that has even changed erosion behavior since the Cretaceous period. Even strong winds cannot damage the earth. From a botanical point of view, the herb belongs to an order similar to sweet tastes, the so-called Poales. Our food grade wheat, oats, rice, millet or even corn are considered for this purpose. How important it is to optimally prepare the soil for turf growth becomes clear when you take the phrase “no grass grows” literally. Therefore, you must take special care - both at the initial stage and after rooting your roller skate.
Main stages of Earth's evolution
History of the Earth by modern ideas is approximately 4.6 billion years old. Numerous results of studying the earth's crust (the chemical composition and structure of rocks, their distribution in depth, the content of radioactive isotopes, remains of fossil living organisms) made it possible to establish a picture of the formation and development of the planet and determine the age of the biosphere. The entire history of the Earth’s existence is divided into time periods, each of which is characterized by certain physical, chemical, climatic conditions, as well as stages of the evolution of living nature.
What can be done against fungal attack on turf?
Ideally, fungi will not give you a chance to attack your turf and take preventive measures. Prevention is worth it and is not difficult to do. If you follow a regular lawn care routine, you have already taken a big step in the right direction. Regularly mow the same optimal lawn with optimal height creates conditions in which fungal conditions are difficult. But be careful: cutting your turf short will do the exact opposite. Soiling too often or too thickly favors fungal infestation and also leaves a shoal or dense mulch in the fall.
The age of rocks is determined by analysis of isotopic composition and, in particular, by radiocarbon dating. Its essence lies in the fact that the tissues of living organisms contain a small and constant amount of carbon C14, which decays with a half-life of 5760 years. As a result of this decay, the ratio of the masses of C 14 to C 12 in the remains of living organisms decreases with the time elapsed after the death of the organism. By determining this ratio in rocks containing remains of living organisms, the age of these rocks can be calculated.
They should be removed at regular intervals and especially before winter, because too dense, poorly ventilated swords will also colonize fungi. When to Apply Fertilizer: The median is the correct dose for optimal soil pH. Fertilization that is too low and too high as a result of too intense fertilization favors fungal infection. It is also stimulated by too much humidity in shady areas or too much soil moisture and waterlogging. Fungi settle in the root zone of the grass plant.
Time periods of the geochronological scale are divided into eras, periods, etc. The first, earliest time period, called the “catarchaic” or “lunar period”, corresponds to the formation of the Earth, its atmosphere, aquatic environment. Life did not exist in any form during the first 1 - 1.5 billion years, since the appropriate physicochemical conditions had not yet arisen. At an early stage, intense tectonic processes occurred, accompanied by a redistribution of chemical elements and compounds throughout the depths of the Earth. Nuclear decay reactions that occurred in the center and deep layers of the planet (they are still taking place) contributed to the heating of the Earth. The atmosphere was dominated by sulfur, chlorine, and nitrogen compounds; the oxygen content was hundreds of times less than now. Heavier elements moved toward the center of the Earth and then formed the core, while lighter elements moved toward the surface. Intense volcanic and thunderstorm processes contributed to the formation of an aquatic environment - and the first organic molecules began to form in it.
Does the weed grow through the turf?
It is quite possible that weeds will grow from underground if you prepare it carefully and put peat well, water it regularly and feed it optimally. Because wind, birds and insects constantly transport weed seeds through the air and land on your peat, from time to time it happens that they take up residence there and begin to grow. Therefore, remove the grass in the spring, where weed seeds provide ideal soil for growth. The root formation caused by scarification also prevents the spread of unwanted plants such as dandelions, clovers or daisies.
Archean and Proterozoic are the two largest eras, during which life began to form at the level of microorganisms. These two eras are combined into “nadera” - cryptozoic (the time of hidden life). The first multicellular organisms appeared at the very end of the Proterozoic about 600 million years ago.
Approximately 570 million years ago, when favorable conditions for life were practically formed on Earth, the rapid development of living organisms began. From this moment on, the “time of obvious life” began - the Phanerozoic. This segment of geological history is divided into 3 eras - Paleozoic, Mesozoic and Cenozoic. The last era from the point of view of geo- and biology continues to this day. It should be noted that the emergence and development of life on earth led to a significant change in the solid shell of the Earth (lithosphere), hydrosphere and atmosphere, and the emergence of intelligent life (humans) in a short time interval caused global changes in the evolution of the planet.
This allows water and fertilizer to penetrate the soil more easily. Return your thorn the second year after growth, and then every spring when the grass grows. Then carefully remove the material that subsequently forms on the surface of the lawn using a rake. Of course, you can also carefully root-prun individual plants.
Avoid using chemical weed control on your turf and instead invest in regular maintenance to keep weeds out of the woods. About three to four weeks after installation is the ideal time to fertilize. However, this depends on the quality of the soil, the color of the lawn and the density of the grass. Light spots and loose, very thin growth on the lawn indicate a lack of nutrients, while a dark green, rich color and dense scar is achieved through optimal care.
Differences in the composition of rocks from one era (period) to another, in turn, are caused by sharp changes in the natural, climatic and physical conditions on the planet. It has been established that the climate on Earth has changed many times; warmings were replaced by sharp cold snaps, and land uplifts and subsidences occurred. There have also been major space disasters: collisions with meteorites, comets and asteroids. A large number of large meteorite craters have been discovered on Earth. The largest of them on the Yucatan Peninsula has a diameter of more than 100 km; its age is 65 million years, practically coinciding with the end of the Cretaceous and the beginning of the Paleogene period. Many paleontologists associate the extinction of dinosaurs with this major catastrophe.
However, you can't go wrong if you fertilize your sod during the spring to fall growing phase, approximately every six to eight weeks. In addition, you will receive specially formulated lawn roller fertilizer from specialist retailers. This encourages the movement of grass plants and the lawn can be protected from nuisance weed growth. With fertilizers based on rock meal and natural microelements, mycorrhizal cultures and nitrogen-containing bacteria, your lawn is well supplied.
Also, be sure to fertilize before winter time to prepare peat for the colder months. Crushing minerals between diamonds, experts from the University of Utah suggest the existence of an unknown layer inside the Earth where the stone becomes three times harder.
Changes in climate and temperature are largely due to astronomical factors: the tilt of the earth's axis (changed many times), disturbances of the giant planets, the activity of the Sun, and the movement of the solar system around the Galaxy. According to one hypothesis, abrupt climate changes occur once every 210 - 215 million years (galactic year), when the Solar system, revolving around the center of the Galaxy, passes through a gas and dust cloud. This contributes to the weakening of solar radiation and, as a result, cooling of the planet. At these moments, ice ages begin on Earth - polar caps appear and grow. The last ice age began approximately 5 million years ago and continues to this day. The Ice Age is characterized by periodic temperature fluctuations (every 50 thousand years). During cold spells (ice ages), glaciers can spread from the poles to the equator by up to 30 - 40 degrees. We are now living in the “interglacial” period of the Ice Age. The legacy of the Ice Age is the permafrost zone (in Russia, over half of its territory).
The discovery could explain the mystery of why blocks of Earth's tectonic plates that sink sometimes stagnate and condense to depths of 930 miles. “The Earth has many layers, like an onion,” says Lowell Miyagi, assistant professor of geology and geophysics at the University of Utah, US. "Most layers are determined by the minerals present, essentially we have discovered a new layer on Earth that is not determined by the minerals present, but by the strength of those minerals," he says.
Oceanic plates collide with continental plates along the coasts of Chile, Peru, Mexico, the Pacific Northwest, Alaska, Kamchatka, Japan and Indonesia. At these locations, the leading edge of the oceanic plate bends so that the plate sinks beneath the continent, causing earthquakes and volcanism as slabs descend into the mantle, which is like the bottom of a conveyor belt. The subduction process is slow, with an average plate descent of about 300 million years, Miyagi estimates.
The materials that make up the solid Earth are opaque and dense. Direct studies of them are possible only to depths constituting an insignificant part of the Earth's radius. The deepest wells drilled and projects currently available are limited to depths of 10 - 15 km, which is just over 0.1% of the radius. It is possible that it will not be possible to penetrate to a depth of more than a few tens of kilometers. Therefore, information about the deep interior of the Earth is obtained using only indirect methods. These include seismic, gravitational, magnetic, electrical, electromagnetic, thermal, nuclear and other methods. The most reliable of them is seismic. It is based on the observation of seismic waves generated in the solid Earth during earthquakes. Just as X-rays make it possible to study the state of the internal organs of a person, seismic waves, passing through the bowels of the earth, make it possible to get an idea of the internal structure of the Earth and the change in the physical properties of the substance of the earth's bowels with depth.
Seismic waves are divided into longitudinal and transverse in accordance with the fact that the displacement of the substance during vibrations is directed along and across the direction of propagation of the wave. Longitudinal waves can propagate in both liquid and solid matter, while transverse waves can propagate only in solid rocks. In addition, the speed of longitudinal waves in a solid is approximately 1.7 times higher than the speed of transverse waves. By having a network of seismic stations on the Earth's surface, recording readings from instruments that record earthquakes - seismographs - and comparing these readings, it is possible to determine the epicenter of an earthquake, as well as the speed of wave propagation in various internal regions of the planet. Since the speed of wave propagation depends on the density and elasticity of the substance, it is possible to obtain data on these parameters, as well as on the aggregate state of the substance (liquid or solid) throughout the entire interior of the Earth.
In addition to the passive study of seismic waves, the method of deep seismic sounding, proposed in 1949 by the Soviet seismologist G.A., is currently used. Gamburtsev. This method uses seismic waves generated by an explosion, which are recorded by seismographs installed at intervals of only 200 - 500 m from each other. This method gives the most reliable results, but its practical use requires a lot of money.
As a result of seismic studies, it was determined that the inner region of the Earth is heterogeneous in its composition and physical properties, and forms a layered structure (Fig. 11.1). Here we will only briefly list the dimensions and main physical parameters of these layers:
Rice. 11.1. Inner shells of the Earth
1. The top layer of the Earth is called the earth's crust and is divided into several layers. The uppermost layers of the earth's crust consist mainly of layers of sedimentary rocks, formed by the deposition of various small particles, mainly in the seas and oceans. These layers contain the remains of animals and plants that inhabited the globe in the past. The total thickness (thickness) of sedimentary rocks does not exceed 15 - 20 km.
The difference in the speed of propagation of seismic waves on continents and on the ocean floor led to the conclusion that there are two main types of crust on Earth: continental and oceanic. The thickness of the continental-type crust is on average 30 - 40 km, and under many mountains it reaches 80 km in places. The continental part of the earth's crust is divided into a number of layers, the number and thickness of which vary from region to region. Usually, below the sedimentary rocks, two main layers are distinguished: the upper one is “granite”, close in physical properties and composition to granite, and the lower one, consisting of heavier rocks, is “basaltic” (it is assumed that it consists mainly of basalt). The thickness of each of these layers is on average 15 - 20 km. However, in many places it is not possible to establish a sharp boundary between the granite and basalt layers. The oceanic crust is much thinner (5 - 8 km). In composition and properties, it is close to the substance of the lower part of the basalt layer of the continents. But this type of crust is characteristic only of deep areas of the ocean floor, at least 4 thousand m. At the bottom of the oceans there are areas where the crust has a continental or intermediate type structure. The Mohorovicic surface (named after the Yugoslav scientist who discovered it), at the boundary of which the speed of seismic waves changes sharply, separates the earth's crust from the mantle.
2. The mantle extends to a depth of 2900 km. It is divided into 3 layers: upper, intermediate and lower. In the upper layer, the velocities of seismic waves immediately beyond the Mohorovicic boundary increase, then at a depth of 100 - 120 km under the continents and 50 - 60 km under the oceans, this increase is replaced by a slight decrease in velocities, and then at a depth of 250 km under the continents and 400 km under the oceans, the decrease again replaced by growth. Thus, in this layer there is a region of reduced velocities - the asthenosphere, characterized by a relatively low viscosity of the substance. Some scientists believe that in the asthenosphere the substance is in a “porridge-like” state, i.e. consists of a mixture of solid and partially molten rocks. The asthenosphere contains hotspots of volcanoes. They are probably formed where, for some reason, the pressure and, consequently, the melting point of the asthenosphere matter decreases. A decrease in the melting point leads to the melting of the substance and the formation of magma, which can then flow through cracks and channels in the earth's crust to the surface of the Earth.
The intermediate layer is characterized by a strong increase in the velocities of seismic waves and an increase in the electrical conductivity of the Earth's substance. Most scientists believe that in the intermediate layer the composition of the substance changes or the minerals composing it transform into a different state, with a more dense “packing” of atoms. The bottom layer of the shell is homogeneous compared to the top layer. The substance in these two layers is in a solid, apparently crystalline state.
3. Beneath the mantle is the earth's core with a radius of 3471 km. It is divided into a liquid outer core (layer between 2900 and 5100 km) and a solid nucleolus. During the transition from the mantle to the core, the physical properties of the substance change sharply, apparently as a result of high pressure.
The temperature inside the Earth increases with depth to 2000 -3000 0 C, while it increases most rapidly in the earth's crust, then it slows down, and at great depths the temperature probably remains constant. The Earth's density increases from 2.6 g/cm3 at the surface to 6.8 g/cm3 at the boundary of the Earth's core, and in the central regions it is approximately 16 g/cm3. The pressure increases with depth and reaches 1.3 million atm at the boundary between the mantle and the core, and 3.5 million atm in the center of the core.
Outer shells of the Earth
In addition to the hard outer shell - lithosphere They also secrete an aqueous shell - hydrosphere and the air shell - atmosphere. More precisely, the hydrosphere is understood as the totality of all the waters of the Earth that are in solid, liquid and gaseous states. There is more liquid water on Earth - a volume of about 1,370. 10 24 cm 3. It forms the World Ocean on the surface of the Earth, total area which is equal to 3.61. 10 18 cm 2, i.e. 70.8% of the area of the entire earth's surface. Due to its unique properties, water is extremely important for creating an optimal thermal regime on Earth. It was in it that organic life originated and without it would have been impossible.
The bulk of the ice is located on land - mainly in Antarctica and Greenland. Its total mass is about 2.42. 10 22 If this ice melted, the level of the World Ocean would rise by about 60 m. At the same time, 10% of the land would be flooded by the sea.
Water is gradually evaporating from the surface of the World Ocean. It is picked up by air currents and transported over vast distances. After a series of transformations (condensation, sublimation, coagulation, etc.), the evaporated moisture falls out of the atmosphere in the form of precipitation. Not all moisture returns directly to the oceans. Part of the precipitation falls on land, from where it is carried by rivers to the seas and oceans. Every year, rivers bring more than 35 tons of water from land to the oceans. 10 18 g water. During its journey over land, water dissolves various salts, captures small and sometimes large particles and carries it all out to the sea. The total amount of mineral matter carried by rivers into the World Ocean per year is approximately 35. 10 14 Of these 18 . 10 14 g precipitates, and 17 . 10 14 g remain dissolved.
The water cycle on Earth has existed for millions of years. This may be why the water of the seas and oceans is salty, although there is no consensus on this matter.
The atmosphere is a gaseous shell that surrounds the Earth and rotates with it as a single whole. The atmosphere was formed mainly from gases released by the lithosphere after the formation of the planet. Over billions of years, the Earth's atmosphere has undergone significant evolution under the influence of numerous physicochemical and biological processes: dissipation of gases into outer space, volcanic activity, dissociation (splitting) of molecules as a result of solar ultraviolet radiation, chemical reactions between atmospheric components and rocks, respiration and metabolism of living organisms.
A column of air above one square centimeter of the earth's surface has a mass of about 1 kg, and the mass of the entire atmosphere is 5.16. 10 21
The Earth's atmosphere has a layered structure. There are the troposphere, stratosphere, mesosphere and thermosphere.
The troposphere is the area adjacent to earth's surface an area in which the temperature decreases more or less uniformly with altitude to -50 0 C and below. The upper boundary of the troposphere decreases when moving from the equator to the poles from 17 to 9 km. The troposphere contains over 80% of the mass of the atmosphere and almost all water vapor. Physical processes take place in it that determine this or that weather. All transformations of water vapor take place in the troposphere. Clouds form in it and precipitation forms, and turbulent and convective mixing is very developed.
The stratosphere is characterized by constant or increasing temperature with height and exceptional dryness of the air. The upper boundary of the stratosphere is located on average at altitudes of 50 - 55 km. The temperature of the stratosphere increases with altitude, reaching 0-10 0 C at the upper limit. Processes in the stratosphere have virtually no effect on the weather.
The mesosphere is a layer lying above the stratosphere and characterized by a decrease in temperature with height. The upper boundary of the mesosphere coincides with the minimum temperature (about 90 0 C) and is located at an altitude of about 85 km.
The thermosphere is located above the mesosphere. The temperature in it rises rapidly, reaching 1000 - 2000 0 C at an altitude of 400 km. Above 400 km, the temperature hardly changes with altitude. Temperature and air density greatly depend on the time of day and year, as well as solar activity. During the years of maximum solar activity, the temperature and air density in the thermosphere are significantly higher than in the years of minimum.
It should be noted that all the values given here were obtained by averaging them over large time intervals and over huge areas. Without a doubt, the instantaneous parameters of the atmosphere differ significantly from the average, since the atmosphere is an extremely variable environment.
It took nature several billion years for the Earth’s soil to acquire the properties that allowed vegetation to appear on our planet. At first, instead of soil, there were only rocks, which, due to the influence of rain, wind, and sunlight on them, began to gradually become crushed.
The destruction of the soil occurred in different ways: under the influence of the sun, wind and frost, rocks cracked, were polished with sand, and sea waves slowly but surely broke huge blocks into small stones. Finally, animals, plants and microorganisms made their contribution to the formation of soil, adding organic elements (humus), enriching upper layer land with waste products and their residues. The decomposition of organic elements when interacting with oxygen led to various chemical processes that resulted in the formation of ash and nitrogen, which turned rocks into soil.
Soil is the modified loose upper layer of the earth's crust on which vegetation grows. It was formed as a result of the transformation of rocks under the influence of dead and living organisms, sunlight, precipitation and other processes due to which soil erosion occurred.
Due to this transformation of huge, hard rocks into a loose mass, the top layer of soil acquired an absorbent surface: the structure of the soil became porous and breathable. The main importance of soil is that, being penetrated by the roots of plants, it transfers to them all the nutrients necessary for growth, and combines two features necessary for the existence of plants - minerals and water.
Therefore, one of the main characteristics of the soil is a fertile layer of soil, which allows for the growth and development of plant organisms.
In order for a fertile layer of soil to form, the soil must contain a sufficient amount of nutrients and have the necessary supply of water, which would not allow plants to die. The value of land largely depends on its ability to deliver nutrients to the roots of plants and provide them with access to air and moisture (water in the soil is extremely important: nothing will grow if there is no liquid in the soil that will dissolve these substances).
The soil consists of several layers:
- The arable layer is the top layer of soil, the most fertile layer of soil, which contains the most humus;
- Subsoil - consists mainly of rock remains;
- The lowest layer of soil is called “bedrock.”
Soil acidity
A very serious factor that affects soil fertility is soil acidity - the presence of hydrogen ions in the soil solution. The acidity of the soil is increased if the pH is below seven, if it is higher it is alkaline, and if it is equal to seven it is neutral (the concentration of hydrogen ions (H+) and hydroxides (OH-) is the same).
A high level of acidity in the top layer of soil negatively affects plant growth, since it affects its characteristics (size and strength of soil particles), applied fertilizers, microflora and plant development. For example, increased acidity disrupts the structure of the soil, since beneficial bacteria cannot develop normally, and many nutrients (for example, phosphorus) become difficult to digest.
Too much high level acidity makes it possible for toxic solutions of iron, aluminum, manganese to accumulate in the soil, while the intake of potassium, nitrogen, magnesium, and calcium into the plant body decreases. The main feature high level acidity is the presence under the upper dark layer of earth of a light layer, the color of which resembles ash, and the closer this layer is to the surface, the more acidic the soil and the less calcium it contains.
Types of soil
Since absolutely all types of soil are formed from rocks, it is not surprising that the characteristics of the soil largely depend on chemical composition and physical characteristics of the parent rock (minerals, density, porosity, thermal conductivity).
Also, the characteristics of the soil are influenced by the exact conditions under which the soil was formed: precipitation, soil acidity, wind, wind speed, soil and environmental temperature. Climate also has an indirect effect on the soil, since the life of flora and fauna directly depends on the temperature of the soil and the environment.
Soil types depend largely on the size and number of particles that are present in them. For example, damp and cold clay soils are formed by sand particles tightly adjacent to each other, loamy soil is a cross between clay and sand, and rocky soil contains a lot of pebbles.
But peat soil includes the remains of dead plants and contains very few solid particles. Any soil on which plant organisms grow has a very complex structure, since in addition to rocks it contains salts, living organisms (plants), and organic substances that were formed as a result of decay.
After soil analysis was done in different regions of our planet, a soil classification was created - a set of similar areas that had similar soil formation conditions. Soil classification has several directions: ecological-geographical, evolutionary-genetic.
In Russia, for example, the ecological-geographical classification of soils is mainly used, according to which the main types of soil are turf, forest, podzolic, chernozem, tundra, clayey, sandy, and steppe soils.
Chernozem
Chernozem, which has a lumpy or granular structure, is considered the most fertile soil (humus content is about 15%), characteristic of a temperate continental climate, in which dry and wet periods alternate, and above-zero temperatures predominate. Soil analysis showed that chernozem is rich in nitrogen, iron, sulfur, phosphorus, calcium and other elements necessary for the favorable functioning of plants. Chernozem soils are characterized by high water-air characteristics.
sandy lands
Sandy soil is characteristic of deserts and semi-deserts. It is a crumbly, granular, devoid of cohesion soil, in which the ratio of clay to sand is 1:30 or 1:50. It does not retain nutrients and moisture well, and due to the poor vegetation cover it is easily susceptible to wind and water erosion. Sandy soil also has its advantages: it does not become waterlogged, since water in the soil easily passes through the coarse-grained structure, air reaches the roots in sufficient quantities, and putrefactive bacteria do not survive in it.
Forest lands
Forest soils are characteristic of temperate forests northern hemisphere and their properties directly depend on the forests that grow in it and have a direct impact on the composition of the soil, its air permeability, water and thermal regimes. For example, deciduous trees have a positive effect on forest soils: they enrich the soil with humus, ash, nitrogen, neutralize acidity, creating favorable conditions for the formation of beneficial microflora. But coniferous tree species have a negative impact on forest soils, forming podzolic soil.
Forest soils, no matter what trees grow on them, are fertile, since nitrogen and ash, which are found in fallen leaves and needles, return to the soil (this is their difference from field soil, where plant litter is often removed along with the harvest).
Clay soils
Clay soils contain about 40% clay and are moist, viscous, cold, sticky, heavy, but rich in minerals. Clay soil has the ability to retain water for a long time, slowly become saturated with it and very slowly let it pass into the lower layers.
Moisture also evaporates slowly, allowing plants growing here to suffer less from drought.
The properties of clay soil do not allow the plant root system to develop normally, and therefore most of the nutrients remain unclaimed. In order to change the composition of the top layer of soil, it is necessary to apply organic fertilizers over several years.
Podzolic soil
Podzolic soils contain from 1 to 4% humus, which is why they are characterized by a gray color. Podzolic soil is characterized by a very low content of nutrients, high acidity, and therefore it is infertile. Podzolic soils are usually formed near coniferous and mixed forests of the temperate zone, and their formation is strongly influenced by the predominance of precipitation over evaporation, low temperatures, reduced microbial activity, poor vegetation, which is why podzolic soils are characterized by a low content of nitrogen and ash (for example, taiga soils , Siberia, Far East).
To use podzolic soils in agricultural work, farmers need to make a lot of effort: apply large doses of mineral and organic fertilizers, constantly regulate the water regime, and plow the soil.
Sod soil
Soddy soils are fertile and characterized by a low or neutral level of acidity, a high amount of humus (from 4 to 6%), and they also have soil properties such as water and air permeability.
Soddy soils are formed under developed grass cover, mainly in meadows. Soil analysis showed that the turf soil contains a large amount of magnesium, calcium, ash, and humus contains a lot of humic acids, which upon reaction form humates - insoluble salts that are directly involved in the formation of the lumpy-grained structure of the soil.
Tundra land
Tundra soils are poor in minerals and nutrients, very fresh and contain little salt. Due to weak evaporation and frozen soil, tundra soils are characterized by high humidity, and due to the insufficient amount of vegetation and its slow humification, low humus content. Therefore, tundra soils contain a thin peaty layer in their upper layer.
The role of soil
The importance of soil in the life of our planet is difficult to overestimate, since it is an indispensable element of the earth’s crust, which ensures the existence of plant and animal organisms.
Since a large number of different processes (among them organic substances) flow through the upper layer of the earth, it is a connecting link between the atmosphere, lithosphere and hydrosphere: it is in the upper layer of the earth that chemical compounds are processed, decomposed and transformed. For example, plants that grow in the soil, decomposing along with other organic substances, are transformed into minerals such as coal, gas, peat, and oil.
The protective functions of the soil are also important: the soil neutralizes substances found in it that are dangerous to life (this is especially important, since soil pollution has recently become catastrophic). First of all, these are toxic chemical compounds, radioactive substances, dangerous bacteria and viruses. The safety margin of the top layer of the earth has a limit, therefore, if soil pollution continues to increase, it will no longer cope with its protective functions.