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Fertilityand humus - concepts that are closely related. From the Latin language, this term is translated as soil or land. Although today farmers without any problems grow crops in hydroponics or artificial soil, yet this component of fertility is indispensable. To increase the percentage of yield, you first need to find out what soil humus is, and then consider the process of its formation.
Humus is. ..
Ecological dictionaries unanimously say that these are humus plants in tandem with organic animal waste. Even in ancient times, our ancestors noticed that the darker the land, the more abundant and high-quality harvests it gives. Coloring is the first sign that indicates the presence in the soil of the nutrient medium for the root system of plants.
So how is humus formed? In the upper layer of the soil, complex biochemical processes occur - decomposition of organic remains without oxygen. They cannot occur without participation:
- soil microorganisms;
Dying off, they leave behind a significant imprint on soil formation. Here also accumulated decomposed waste products of these organisms. In turn, such organic substances are resistant to microbes, which allows them to accumulate in the soil horizon.
This biomass serves as a depot for all higher organisms. The components contained in it saturate the roots of plants with energy and also nourish them with all the necessary elements:
- with gumin;
- humic acids;
- humic compounds.
The power of such a cover can reach( in temperate latitudes of the planet) up to 1.5 meters. In some territories it is 10-16% of the land, while in others it is only 1.5%.At the same time, peatlands contain about 90% of such organic formations.
The formation of humus directly depends on the process of mineralization - decomposition of biomass( under the influence of oxygen) into simple mineral and organic compounds. Under normal natural conditions, this occurs evenly, without prejudice to humification.
Before drawing attention to the beneficial properties of this soil cover, it is necessary to consider its composition. The greatest concentration of useful elements is contained exclusively in the upper part of the horizon. When deepening, they become smaller, since all the “participants” of this process live at a level of 50-70 cm from the surface. Therefore, the formation of fertile layers is impossible without:
- certain species of fungi;
Recycling of organic components, as well as excrement of invertebrates, leads to the formation of priceless humus. It is the worms that are crucial in its formation. It should be noted that about 450-500 individuals live in 1 m² of humus. Each of them eats plant residues and bacteria. The organic matter they put off makes up a large percentage of the nutrient biomass. The composition of humus includes such chemical elements( the percentage depends on the type of soil):Fulvic acid
- ( 30 - 50%).Nitrogen-soluble soluble( high molecular weight) organic acids. They lead to the formation of compounds that destroy mineral formations.
- Humins( 15 - 50%).These include elements that have not completed the process of humification. However, their livelihoods depend on minerals.
- Resurfacing( from 2 to 6%).
- Humic Acids( 7–89%).They are insoluble, although they can decompose into separate elements under the influence of alkalis. Each of them contains one of the leading components: nitrogen, oxygen, hydrogen and carbon. When acids come into contact with other components, salts can form in the soil.
- Insoluble residue( 19 - 35%).This applies to various saccharides, enzymes, alcohols and other elements.
The table of humus content in the main soil groups shows the amount of nitrogen and carbon for every 100 or 20 cm of soil. Measurement is carried out in t / ha. This is the general picture of the reserves of fertile land in Russia.
If fertilizer is applied too often and in large quantities( mineral, in particular, nitrogenous), this will lead to a rapid decomposition of biomass. In the first years, the yield, of course, will increase several times. But over time, the volume of the fertile layer will decrease significantly, and the yield will deteriorate.
Useful Properties of
In agriculture, the preservation of this organic horizon is considered the most important. Over the past half century, due to erosion in Russia, as well as Ukraine, the upper cover has decreased by almost half. The impact of wind and water led to the blowing off / washing off of rich layers of soil. Ecology and agrarians consider the content of humus in the soil as a factor of fertility, and the main criterion for the purchase of land. After all, it is he who is responsible for the qualitative characteristics of the soil, and for what reasons:
- It is focused on the abundance of nutrients that are needed for productive plant activity. This is almost 99% of the nitrogen available in nature, as well as more than 60% of the total phosphorus.
- Promotes saturation of the earth with oxygen, making it more loose. Due to this, the root systems of the crops and the microorganisms living in the soil receive a sufficient portion of air.
- Forms a soil structure. As a result, clay and sand do not accumulate. Organic compounds glue mineral particles into lumps, forming a kind of lattice. Moisture passes through it, which is retained in the formed voids. So the vegetation gets water. Also, the porous structure protects the earth from sudden changes in temperature and erosion anomalies.
- Humus promotes uniform heating of the soil. Complex biochemical processes take place in this layer. The consequence of such reactions is the release of heat. As noted above, the fertile soil has a darker shade. Brown-black tones best attract and absorb ultraviolet rays.
Organic compounds protect land from the corrupting influence of harsh chemicals from human activity. These elements "preserve" resinous carbon, salts, metals and radionuclides, leaving them forever in the bowels of the earth and not allowing the plants to assimilate them.
The only problem for all farmers is the natural area of crop cultivation, as well as the soil types in which the humus content( table is given in the article) is strikingly different. Therefore, in order to increase the fertility of their lands, it is necessary to determine the level of biomass in them, taking as a basis the natural conditions of the region.
Map of humus reserves
In areas where the climate is very harsh, the process of soil formation is extremely slow. Due to the weak warming of the upper layer of the plant and microorganisms, they lose favorable conditions for a full-fledged existence.
Here you can see huge areas consisting of coniferous trees and shrubs. The slopes are mostly moss covered. In the tundra, the humus content is 73–80 t / ha in the one-meter layer. These areas are so wet that they lead to the accumulation of clay rocks. As a result, tundra soils have the following structure:
- topcoat - bedding consisting of undecomposed plant residues;
- humus layer, which is very weak;
- helium layer( comes with a bluish tinge);
Almost no oxygen penetrates into such soils. Air is essential for the microbiological activity of organisms. Without it, they die or freeze.
In this area there are deciduous trees. They form dense mixed forests. In the steppe zones grows not only moss, but also herbal plants. Spring( often melting snow) and autumn rainy seasons excessively moisten the soil. Such streams wash off the humus horizon reserves.
Here it is formed and lies under the forest floor. Many sources provide different indicators of humus content in the taiga. For the following soil types they are( per 1 m², t / ha):
- podzolic( strong, medium and weak) - from 50 to 120;
- gray forest - 76 or 84;
- sod-podzolotnye - not more than 128, and not less than 74;
- taiga-freezing contain a very low percentage.
In order to grow crops on such lands, the beds should be regularly fertilized with high-quality substances. Only in this case, you can achieve high yields.
All known varieties of black soil are considered to be the leader and favorite in this fertility rating. Organic humus in them reaches a depth of 80 cm or 1.2 meters. By law, they can be called the most fertile lands. This is a favorable soil for the growth of cereals( wheat), sugar beet, corn or sunflower. From the following list you can see the variation of humus content in various types of black soil( t / ha, per 100 cm):
- typical( 500-600);
- Podzdzelenny( up to 400);
- leached( within 550);
- powerful( more than 800);
- South West Caucasus( 390);
- degraded( up to 512).
It should be understood that the indicators for virgin, arable and developed types of land are different. For familiarization with the composition of each of these groups, a table is given. In the steppe and arid regions chestnut soils are distributed that contain no more than 100-230 t / ha of humus. For desert( brown and gray types of soil cover) regions, this figure is about 70 t / ha. As a result, farmers constantly have to deal with salinization of fields.
Drought is the main enemy of such varieties of land. Therefore, plantations may require abundant irrigation.