Composition of the soil: how it is formed and the main parts, scheme and structure, functions

Good soil is necessary for the growth and development of plants, so that they give a rich harvest. It is a support for the roots, a source of nutrition and water. Complex organic substances are converted in it to simple mineral substances, which are absorbed by plants. Consider what is in the composition of the soil, what layers it consists of, how it is formed. Why do we need soil microorganisms.

What is soil made of

It contains several components: organic and mineral nature, moisture and air.

Mineral base

Considered one of the main characteristics of the soil.This is its solid part, represented by minerals, it was formed as a result of the processes of weathering of rocks and their transformation. The soil cover was formed under the influence of physical and chemical factors and microorganisms. The main component of the mineral part of the soil is silicon-oxygen compounds, for example, silicon oxide. Iron and aluminum are present in large quantities in ferrosilicate and aluminosilicate soils.

The mineral part contains primary and secondary minerals. Primary prevail in sandy and sandy loamy, in loamy - both, in clayey - secondary.

The earth also contains mineral s alts: carbonates, sulfates, phosphates, nitrates and chlorides of various elements. They are soluble in water, in saline soils their quantity is greater than in ordinary ones. There are also insoluble or hardly soluble s alts. Their main source is also mountain soil-forming rocks.

Organic

Located in the surface layer of the earth. These are the remains of organic matter (plant and animal tissues that have partially retained their structure and shape) that have entered the earth, they are in the form of organic or organomineral compounds. Humus also belongs to the constituent parts of this part of the soil. Humus is the result of the process of formation of nitrogen-containing compounds that have a complex structure.

Humus is a fertile part of the soil, consists of humic and fulvic acids and their s alts. Humic acids are poorly soluble in water, black or dark brown in color. Fulvic acids dissolve well in water, give the soil a yellowish color, and participate in the soil-forming process of podzols. Humus also contains non-specific substances: proteins, amino acids, carbohydrates, monosaccharides, peptides, purines, resins, lipids, lignin, organic acids and tannins, aldehydes, alcohols.

What other layers does the soil consist of?

The liquid part of the soil is represented by the soil solution, it is the most active and mobile. From it, plants get water and the nutrients dissolved in it. The composition and concentration of the soil solution vary depending on the physicochemical and biological processes occurring in the earth. Air is present in the pores; it has more carbon dioxide and less oxygen than atmospheric air. Its composition is also variable and depends on gas exchange between the soil and the atmosphere.

All components of the soil are interconnected and mutually influence each other, a mobile balance is established between them. The entry of s alts into the soil solution depends on the weathering and destruction of minerals, the transformation of organic residues, and the entry of mineral fertilizers from outside. The soil profile diagram shows that it consists of several layers, in the upper there is more moisture and air than in the lower.

How is it formed?

Formation of soil is a long process, it proceeds continuously. Minerals are formed from rocks, which are gradually destroyed under the influence of water, air, heat, microorganisms. All these components are themselves part of the soil.

The main source of organic matter is plants and their remains, which are processed by bacteria. Insects, worms, small animals living in the soil take an active part in the formation of the soil. They process particles of organic matter, mix them with the earth, loosen it.

Different types of soils differ in structure, physical properties, humus content and nutrients, this determines their fertility.

Role of microorganisms in soil formation

Bacteria, fungi and other representatives of microorganisms perform an important function - they regulate metabolism, process plant particles into mineral ones.It occurs as a result of aerobic or anaerobic reactions. In the first case, organic matter is completely converted into simple substances: s alts, carbon dioxide, water. In the second, incomplete decomposition of organic matter occurs with the formation of alcohols and acids.

Both processes can occur simultaneously, but in different types of soil one or the other prevails. The types of bacteria and the reactions they produce depend on the physical characteristics of the soil: aerobic processes predominate in warm and moderately moist soils, and anaerobic processes in cold and waterlogged ones.

What does the term "fertile soil" mean?

Fertile soils are considered to be those that satisfy the needs of plants in water, heat, air and nutrients in the amount in which they need them.They should be light in composition, loose, well warmed up, breathable, contain nutrients and substances in the upper horizon.

All processes that occur in the soil are interconnected. If something is broken, it affects the entire system. The deterioration of the state of the land entails a deterioration in the condition of plants, a decrease in productivity. To determine fertility, you need to pay attention to the chemical composition, acidity, air and moisture permeability.

The composition of the soil affects its characteristics, the main components are the mineral part, organic, liquid and air. Microorganisms and small soil animals play an important role in soil formation.

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