What is the factor of soil formation? What are the factors of soil formation?

Earth is the wealth of all mankind. And we are talking not only about the planet, but also about the reserves of soils on its surface. Without them, there would not be such a diverse flora, and heterotrophs (to which any animal and man refers) could not in principle appear. How did the ground form on the surface of the planet? This is the "guilty" factor of soil formation. More precisely, their whole group.

Main classification

VV Dokuchaev believed that five soil-forming factors should be distinguished:

• Maternal breed.
• Climatic parameters. In general, the climate as a factor of soil formation by many scientists is viewed from a key position, since its role is really impressive.
• Flora.
• Fauna.
• Terrain and past tense.

But these are not all the main factors of soil formation. Today, scientists believe that to this list it is necessary to add two more positions: the effect of water (atmospheric precipitation) and human activity. And now we will understand all the factors in more detail by discussing their characteristics. So, the most important factor of soil formation is the substance that gave rise to the soil.

Mother rocks

As you can understand, these are the minerals from which fertile (or not very) soil was once formed and continues to form. It is from the primary rock that the mechanical, physical, chemical and other properties of the soil depend. Thus, soils originally formed, for example, from granite and similar rocks, may not be equivalent to those that have come out of tuffs and pumice.

What are the parent rocks? They are magmatic, sedimentary and metamorphic. By the way, both granite and pumice with tufa are igneous rocks, but the soils from them are different. What does it depend on, because the factor of soil formation is the same?

How does the ground depend on the origin?

The chemical and mineralogical composition, which depends not only on the rock, but also on the specific region of its origin, plays a huge role in the properties of the soil layer. So, if the mineral is carbonate, has an alkaline reaction (or is close to neutral), then the soil formed on its basis quickly begins to accumulate humus and acquires high fertility. Thus, the main factors of soil formation are extremely important, since the size of potential crops in the future directly depends on them.

If the rock is acidic, then all these processes go several times slower. In the case when the mineral contains a large amount of water-soluble salts, the soil "gets" excessively saline. In addition, the mechanical composition is of great importance, since the heat capacity, moisture capacity and other important parameters depend on it, which directly affects the fertility of the soil in this or that area.

Relief

This factor of soil formation is rarely recalled, but in vain. Indeed, it is the relief that influences the distribution of solar radiation, precipitation and other factors over the surface of rocks, which means that the characteristics of the soil depend on it, which in the end turns out to be "on the way out."

Most radically this manifests itself in the mountainous terrain with the existing pressure, illumination, and radically different temperature conditions. Air masses and their convection are of great importance here, as a result of which huge volumes of air with different temperatures constantly blow the mountainous slopes. In many respects, the relief, as a factor of soil formation, also depends on the climatic features of the terrain, since without the combination of these two conditions, the soil can not form.

Humidity of air is also different, and after "straddling" through mountain ridges, it sharply decreases. As a result, the rock is weathered to various degrees, sedimented, and collapses to form fractions of various sizes.

Perhaps most importantly, however, the effect of lighting and solar radiation, which in different climatic zones is different in order. So, in the Far North there are few soils, and they are extremely scarce, and the rocks have been preserved in perfect condition. Compare this with the desert areas in which the rocks have long been crushed to a state of uniform quartz sand. If you look at the main factors of soil formation in the Orenburg region, the importance of the relief will be even more obvious.

In that area an enormous role is played by the so-called syrtas, that is, relatively low dolly. In combination with the flat terrain, this relief predetermines the high speeds of movement of air masses over the surface of the parent rocks, which leads to their relatively rapid weathering and subsequent destruction.

Under these conditions, the rate of accumulation of humus (and the very presence of organic substances) varies radically, as does the fraction and chemical composition of the resulting soil. Accordingly, it will have a different degree of fertility.

Kinds of soils depending on the difference in terrain

At present, it is considered that as a result of natural processes, three types of soils can be formed, which are also called "moisture horizons":

• Automorphic varieties. Their formation occurs in conditions of free runoff of surface waters and deep occurrence of soil moisture. In this case, the biological factor of soil formation begins to play a predominant role.
• Semi-hydromorphic. The formation of such soils occurs when surface moisture can stagnate for some time on the surface of the parent rocks, and soil sources lie at a depth of no more than six meters.
• Hydromorphic soils. Accordingly, such a soil is formed in those cases when surface waters can remain stagnant for a long time on the surface of the rock, and the soil moisture lies at a depth of not more than three meters.

In all these cases, the anthropogenic factor of soil formation can also be of considerable importance. A person, in the course of his economic activity, often drains or floods large areas of the earth's surface, which greatly affects the characteristics of soil formation.

Erosive processes

If the slope of the surface is 30 degrees or more, then the relief becomes particularly important. So, under these conditions, water erosion is widespread. It acts much stronger than the wind variety, which is common in areas with flat terrain or where the slope of the surface is very small. If you look at the main factors of soil formation in the Orenburg region, this is easily seen. In those parts, the main role in "abrasion" of the surface layer of mineral rocks is played by wind, which can reach extremely high speeds.

The relief plays an important role even in the evolutionary process of flora development in this or that locality. This is most clearly manifested when river beds change or the seas leave (or vice versa, the flooding of areas). This leads to an increase or decrease in the level of soil water, a change in the cycle of soil development (the automorphic type changes to hydromorphic, or vice versa).

Influence of the biosphere

The biological factor in the formation of each soil is the leading one. Only after the first living microorganisms appeared on land, it basically could develop. In principle, the process of soil formation itself can be regarded as a deep interaction between living (microorganisms) and inanimate (destroyed rocks) nature. The mother breed itself during this process is fairly transformed. The main condition that ensures the continuity of soil formation is the influx of radiant solar energy to the surface of the planet.

Atmospheric gases, flora and fauna, products of their vital activity - all these factors and conditions of soil formation "led" to the fact that today we have under our feet a fertile land on which mankind grows food for themselves and feed for farm animals.

Let us reiterate that the kind of "energy meter" is the amount of incoming solar energy. On the surface of the planet, it helps the transition of minerals (that is, inanimate nature) into the living. As you probably guessed, we are talking about the process of photosynthesis. In addition, solar energy helps the transition of dead parts of plants back into the composition of inanimate matter. Due to the continuous process that took place for thousands and millions of years, our planet acquired a unique "soil shell", which is the key to fertility and reproduction of plant biomass.

What else need to mention the factors of soil formation? An essay written even by a middle school student will inevitably consider flora in the context of its important role in the process of accumulation of humus. And this is absolutely true!

The role of plant mass

The main "supplier" of huge volumes of biomass for the whole soil is plants. In addition, they also accumulate solar energy (9.33 kcal / gram). Since on average one hectare grows up to ten tons of plant organisms, this area accumulates about 9.33 * 107 kcal of energy. Such a huge amount of it not only plays an important role in all processes of soil formation, but can also be successfully used by man. So not only the factors of soil formation are plants, but also a valuable energy resource! An ideal example is coal, whose incredible reserves man began to use intensively in the 19th century.

Autotrophs extract from the maternal rock all the necessary mineral substances, and after that they transfer it into the composition of the most complex organic compounds, from which humus is subsequently produced. In part, these compounds return again when they are washed out of dead plant residues by water. These important factors and processes of soil formation contribute, among other things, to uniform mixing of the remaining parent rock and organic matter.

Places of concentration of plant biomass

It is quite natural that in the forests there is a concentration of the largest volume of plant biomass. But this is not exactly an accurate impression, since its really huge increase occurs only in the steppe zone, where no less than 85% of all accumulated organic matter returns to the soil. That is why in the steppes the latter is much more fertile than in the forests, where the soil characteristics in this plan are not too "outstanding". That is, the factors of soil formation, in short, are significantly different, even if they are outwardly similar.

Why is this happening? The fact is that in forests from the soil layer with a low content of humus, many mineral and organic substances are simply washed out under the influence of atmospheric moisture. In the herbaceous biocoenoses, plant remains are densely compressed, forming massive soil horizons. These same conditions contribute to the formation of peat, since there are a lot of moisture on the lower layers and little oxygen, which could stimulate the processes of decomposition. What is the characteristic of soil formation factors?

Ash content of soils

In many ways the process of decomposition of plant residues depends on the chemical composition of the latter. So, the ash content of the needles (that is, the amount of the remaining mineral part) is no more than 1-2%, and in deciduous forests this indicator increases to 4%. In the steppes, the degree of ash content of plant residues can reach 5-6% at once, and in solonchak deserts this indicator increases in general up to 14%! True, in the latter case it does not matter much, since 90% of the mineral part is all the same sodium, calcium and potassium chloride as are found in the salt marshes themselves.

Plants are characterized by the fact that from soils with different mineral composition they take exactly the quantity of salts and compounds that they really need for growth and development. For example, in cereals and diatoms, the concentration of those elements that are mainly characteristic only of silica is very high. In the soil of this particular region, the concentration of these compounds may be negligible. Desert plants are the most vivid example of this statement, since they contain a huge amount of mineral salts.

Why do they need these connections? Everything is simple - the sand in which these autotrophs grow, is extremely meager on the content of all the elements necessary for plants that have to be stored inside their own organism.

The role of wildlife

But if in a school or other educational institution you will be asked the question: "Name the factors of soil formation", do not forget to mention the great role of fauna. Animals in the formation of fertile soil also play a significant role. And here the considerable importance is played by the fact that the soil itself is home to many thousands of species of the most diverse animals and microorganisms. They are the "duty" of grinding and processing the plant mass and its subsequent mixing with the underlying soil horizons.

Mammals and all other vertebrate animals create their burrows and nests in the thickness of the earth. Moles, mole rats, ground squirrels and other normal creatures carry the lower parts of the rock upward. It is in those areas where these animals are many (steppes), there are rich chernozems. Earthworms and larvae also perform a large amount of work on the transformation of the organic constituent of the soil into humus. In addition, invertebrates mix organic and inorganic. Like all natural factors of soil formation, they contribute to the acceleration of the accumulation of organic substances.

Of course, the prevalence of the animal kingdom and its diversity depend entirely on both geographical and climatic factors. The more diverse the flora and fauna, the better and "better" the output of soil, the more organic matter and higher fertility in it.

Climatic factors

Finally consider the climate as a factor of soil formation. A lot depends on the geographic and climatic conditions: it is enough to look at Kazakhstan and the Gobi Desert. The total volume of radiant energy entering the surface of the earth also depends on the location. Accordingly, it is maximum at the equator, minimal - at the pole. Both circumstances negatively affect the processes of soil formation. This is how the soil is formed? Factors of soil formation strongly depend also on the weather.

In many ways the weather and climate depend on the altitude of the terrain above sea level. It should be understood that there are two forms of climate: macro and micro. The greatest contribution to the formation of the soil is taken by wind and various types of atmospheric precipitation. The more diverse the climate, the more "variegated" is the soil at the outlet. Anyway, but the thermal regime plays a significant role in the heat capacity of the soil. This is especially noticeable in mountainous conditions, with different surface slopes.