What is humus? What is humus of soil: composition and properties of fertilizer

Many people are faced with this concept, but far from everyone knows what humus is. Translated from the Latin language, "humus" means "earth", "soil" and is the main organic substance containing nutrients that are simply necessary for plants.

The humus substances refer to a special group of chemical compounds characteristic of the earth's soil cover, that is, they are specific only for the soil. For sure, what is humus, now it became clear, but from what it is formed? From the remnants of plants, animals and microbes as a result of interaction with various components of the environment.

The chemical composition of humus is quite complex. It is characterized by a dark color, which is absent in plants. Humus contains a very valuable humic acid, containing a lot of carbon (about 60%), oxygen (about 35%), nitrogen (an average of 5%), phosphorus, sulfur, iron, and so on. Based on the foregoing, one more answer to the question of what is humus. Humus is a term that unites a huge complex of chemical substances containing an organic part (humic and fulvic acids), an inorganic component (chemical elements having inorganic origin, or in other words minerals that are included in the number of humates and fulvates) in their composition. But we'll talk about this in more detail.

How is humus formed?

With the concept of humus you have already met, the next open is the question of what is the humus of the soil, and how is it formed? Humus of soil is nothing but a product of vital activity of various organisms, primarily earthworms. The process of formation of humus is long-term.

Vegetation, metabolic products, animal remains are all food for organisms that live in the soil. Some part of all this is amenable to mineralization, and the other to biochemical enzymatic decomposition and oxidation (humification), during which the synthesis of organic compounds occurs, and humus is formed. Humus predominates in it, as well as humic acids, which eventually transform, oxidizing as a result to carbon dioxide and water. It is very important that the ways of humus transformation - mineralization or humification - depend directly on soil and climatic conditions. In sufficiently warm and humid climates, the oxidation process takes place very quickly, and practically all the vegetation litter is mineralized, which prevents humus from accumulating in the soil. In cold climates, the transformation of ponds is slightly slower, and their number is small, as a result of which the humus content in the soil is small. The optimal for humification are moderate climates without overmoistening.

So, from all of the above, we can draw the appropriate conclusions:

1. To get a good crop, the plant simply needs carbon dioxide;
2. Carbon dioxide in the soil, as a rule, is formed as a result of the decomposition of plant, animal and microbial remains when interacting with various components of the environment (microorganisms, insects, worms, fungi, etc.);
3. Processed organic remains of plants, animals and microbes and form humus humus, which is an important component of soil fertility.

Functions of humus

1. Physical function. It creates a solid soil structure, which ensures a favorable circulation of water, air of the required temperature and a good growth of roots in the soil. Humus also contributes to the bonding of light soils and loosening of dense soils.
2. Chemical function. It is an excellent repository of nutrients. As a result of the activity of various microorganisms, humus eventually decomposes (the process of mineralization), resulting in the release of the nitrogen, phosphorus, potassium and other elements contained therein.
3. Biological function. Humus creates favorable conditions for the development and further activities of various microorganisms.

Types of humus

• Mor (humus of podzolic soil). Humus of this type is very coarse, containing a large amount of detritus formed with low biological activity in the acidic reaction condition of the medium.
• Moder (humus sod-podzolic soil), formed with medium biological activity in the condition of acid reaction of the medium and weakly interacting with the mineral part of the soil.
• Mull (humus of chernozem), formed at very high biological activity in the condition of neutral reaction of the medium, actively interacting with the mineral part of the soils.
• Anmoor (humus of sod-gley soil), formed in temporarily moistened soils.
• Peat is aligotrophic, which is the "poor humus" of the upper marshes.
• The latter type is eutrophic peat, which is the "rich humus" of lowland bogs.

The importance of humus in soil fertility

Humus actively participates in the process of soil formation. He is given the most important role directly in the formation of the profile of soils. Humus promotes the adhesion of soil particles to aggregates (lumps), creates agronomic valuable structures and plant-friendly physical properties of the soil. It contains the main nutrients for plants and various microelements that are made available to plants after the mineralization process.

Humic substances are food for soil microorganisms. The intensity of various chemical and biological processes that determine the accumulation of substances necessary for plants depends on the content of humus in soils. Humus also contributes to giving the soil a dark color, thus the earth absorbs solar energy better.

Composition and properties of humus

This fertilizer is a complex dynamic complex of organic compounds that are formed during the decomposition of various organic residues.

In the humus of the soil, a specific part (about 90%) consisting of humic substances can be isolated and a non-specific part (the rest) consisting of ungured organic substances. Humus substances of soils, in turn, are represented by:

• Humic acids - high-molecular nitrogen-containing organic compounds having a cyclic structure, insoluble in water and acids, but soluble in weak alkalis, humic acids include carbons (about 50%), hydrogen (5%), oxygen (40%), nitrogen (5%);
• Humates formed as a result of the interaction of humic acids with the mineral part of the soil; Alkali humates are readily soluble in water, thereby forming colloidal solutions; The calcium and magnesium humates are not soluble in water, form a water-resistant structure;
• Fulvic acids - high-molecular nitrogen-containing organic acids, soluble in water, various acids and alkali solutions, in addition, they are capable of dissolving in some organic solvents; In the composition of fulvic acids include carbon, hydrogen, oxygen and nitrogen, I also want to note that these acids contribute to the active destruction of the mineral part of the soil.

The value of humus for plants

All the merits of humic substances are still unknown, therefore only the main ones, firmly rooted in theory and practice, are listed below.

Thus, humus is a fertilizer that promotes:

1. Stimulate the breathing of plants, even with acute oxygen deficiency;
2. Improving the quality of agricultural products;
3. Enhance photosynthesis, stimulate the activity of enzymes, which are directly related to photosynthetic reactions;
4. Acceleration of transport and circulation of nutrients directly inside plants;
5. Growth and development of plants;
6. Activation of root formation and development of the kidneys;
7. Increase of resistance to external adverse effects;
8. The formation of strong compounds with metals, the absorption of phosphates, nitrates and many others;
9. Increase in acidity on the surface of the roots;
10. Increase of resistance of plants to actions of pesticides and herbicides, reduction of their accumulation in final production.

Use of humic substances in medicine

According to the results of various pharmacological tests conducted to determine what humus is, preparations based on humic substances can now be used in medicine and veterinary medicine as a nonspecific drug that contributes to increasing the body's resistance to the effects of various harmful factors.

Medical drugs based on these humic substances in our time already exist on sale. They are actively used in the treatment of radiculitis of various forms, diseases of the ears and nose, pharyngitis, rhinitis, arthritis, polyarthritis, arthrosis and many other diseases. The advantage of these drugs is that they are non-toxic.

Riddles of humic substance

So I went to my logical conclusion about the humus of the soil, its formation, properties and functions. The only thing I want to add is a few words about riddles of humic substances. As is known, they do not have a permanent chemical composition, they do not have a specific molecular mass and a constant single color. Humic substances are still studied by chemists, pedologists, hydrobiologists, physicians, pharmacists with the aim of explaining all the mysteries stored in them, which are predicted to be solved a lot more.