How did the soil form? Soil formation: conditions, factors and process

Soil is a unique natural formation characterized by fertility. Quite often, "land" is used as a synonym for this word. How did the soil form on our planet and what factors influenced this process?

What is the soil?

This is the upper layer of land on the globe. The formation of soil occurred under the influence of a number of factors on rocks . It has its own unique composition, structure and properties.

This is one of the most important components of the biosphere and biocenoses on the Earth, since it maintains the ecological connections of absolutely all living beings with the solid, liquid and gaseous shells of the planet.

Dokuchaev, who most closely studied the question of how the soil formed, called it "a reflection of the landscape," because through it the main features of a particular region are expressed. The soil cover is simultaneously determinant for plant communities, but at the same time itself depends on them.

Soil Properties

The most important property of the soil cover is fertility, expressed in its ability to ensure the development and growth of plants.

Physical properties include:

• Mechanical composition (density and size of soil particles);
• Moisture capacity (ability to absorb and retain water);
• Microbial composition;
• acidity.

Factors of soil formation

The course of the process of soil formation directly depends on the natural conditions or factors in which it occurs. It is also necessary to take into account their combinations, since they determine the direction of the whole process.

The conditions for the formation of soil are divided into five types:

• Soil-forming rock;
• Plant communities;
• Activity of animals and microorganisms;
• Climatic conditions;
• relief;
• Age of the soil cover.

At the present time, two other factors also separately stand out: the effects of water and man. In the question of how soil was formed, the leading factor is biological.

Soil-forming rocks

Absolutely all the soil cover of our planet began to form on the basis of rocks. The determining factor is their chemical composition, since the soil cover absorbs a part of the parent rocks. The nature and direction of the process is affected by the properties of rocks, such as density, porosity, the ability to conduct heat, the size of microparticles.

Climate

The influence of climate on the process of soil formation is very diverse. The main factors of the climate impact are precipitation and temperature regime. Conditions for the process are the amount of heat, humidity, as well as their circulation and distribution in space. The climatic factor is also manifested in the weathering process. The climate also has an indirect effect, since it determines the existence of certain species of plant communities.

Plants and animals

Plants with their root systems permeate the parent rock and deliver to the surface valuable minerals that are subsequently converted into organic compounds.

How is humus formed? The dead parts of plants, saturated with fly ash, remain in the upper horizons. Due to the constant synthesis and decomposition of organic matter on the surface, the soil cover becomes fertile.

Plant communities change the microclimate of the terrain. For example, in the summer the forests are pretty cool, the humidity is higher, the wind strength is minimal , unlike the meadows.

A large number of living organisms live in the upper fertile layer of the Earth. In the process of their life, plants and their organic remains decompose. Subsequently, the animal products are again absorbed by the plants.

The totality of plant and animal communities in certain areas influences the formation of soil type. For example, chernozems are formed only under the meadow-steppe type of vegetation.

Relief

This factor has an indirect effect on the process of soil formation. The relief determines the law of redistribution of moisture and heat. Depending on the height, the temperature regime changes. It is with height that vertical zonation is associated in the mountainous regions of the planet.

The nature of the relief determines the degree of climate impact on soil formation. Redistribution of precipitation occurs due to differences in altitude. In low areas, moisture accumulates, but on slopes and elevations it does not linger. The southern slopes in the northern hemisphere receive more heat than the northern ones.

Age of soils

Soil is a natural body that is constantly evolving. The way we see now the soil cover is only one of the stages of its continuous development. Even if the soil-forming processes in the future do not change, the upper fertile layer can undergo radical changes.

Age is of two types - relative and absolute. Absolute age is the time that has passed since the formation of the soil cover to the present stage of its development. However, not all parts of the earth during the entire period of its historical development were hers. Relative age is the difference in the development of the upper fertile layer within a single territory.

Age can be different - from hundreds to thousands of years.

How did the soil form?

Several generations of scientists and researchers have been interested in this issue. Let us consider below a generally accepted version of the history of the soil-forming process.

The earth has a solid red-hot core, which is surrounded by a hot mantle with a viscous structure. Above is the outer crust, which includes rocks.

Four billion years ago, the Earth began to cool down. In some places, magma appeared on the surface and formed basalts, and where it remained under it, granites were formed. The primary parent breed was changed under the influence of external factors, the synthesis of new mineral substances was gradually occurring.

After the oxygen appeared in the atmosphere, a sedimentary layer began to form. Gradually, as a result of the weathering process, the parent rock became more loose and saturated with oxygen. Thus, clays, sands, gypsum and limestone appeared.

The common view is that life on the planet has existed for more than three billion years. According to recent studies, at this time on Earth already lived bacteria and protozoa single-celled. The first living organisms easily adapted to new environmental factors and were omnivorous. In the process of vital activity, they isolated some enzymes that dissolved rocks and quickly multiplied. Gradually formed soil was inhabited by mosses, lichens, and then plants and animals. As a result of this settlement, humus was formed.

Soil cover is very important for humans. It should be studied for the development of agriculture and forestry, as well as for engineering and construction surveys. Knowledge of the properties of the upper fertile layer of the earth is used to solve problems of geological exploration and extraction of mineral resources, health, and ecology.