Sierozem soils: characteristics and content of humus, where vegetation is also common
Sierozem soils are widespread in Eurasia and on the continents of North and South America. In Russia, gray soils are located in the southeast of its European part, they are in Kazakhstan and Uzbekistan. Formed under dry steppes. Consider what serozems are, their classification, characteristics, how they are formed, how they are used, what vegetation grows on them.
What are gray soils
Sierozems are named so due to the fact that they have a light brown-yellow color. They have a loose structure, a profile with fuzzy transitions between horizons, carbonate content, and are well permeable to water. The parent rock is loam.
Distributed in the foothill pool-deserts of the subtropical zone. Gray soils are characterized by high bioactivity in spring, when it is warm and the soil still retains moisture. This is due to the saturation of the upper horizon with beneficial bacteria, the result of the activity of microorganisms are the processes of mineralization, among which the processes of nitrification and at the same time denitrification predominate.
In gray soils there are blue-green and green 1-cell algae, besides them there are many insects, worms, termites and ants, spiders, reptiles, which also contribute to the formation of the upper soil horizon. Typical vegetation - grasses, sedges, representatives of the Umbelliferae family.
Sierozem soils contain 4% humus, the thickness of the fertile layer does not exceed 0.5 m. The surface of the earth is soddy, permeated with the roots of perennial plants.After the humus horizon there is a transitional layer, gray-yellow, silty-loamy, with many passages of worms and soil animals. Below it is a carbonate-illuvial layer 0.6-1 m thick, dense, without shrew passages. The last horizon is yellowish-yellow, in its lower part at a depth of 1.5 m from the surface there are gypsum inclusions.
Type classification
Serozems are divided into dark, light and typical, the classification is carried out according to the level of soil location above sea level. Dark ones are located on the territory of the foothills and highlands; light - at an altitude of 200-350 m; and typical - at an altitude of 400-1250 m. All types of soils have different humus content, prevailing vegetation, they are formed on different parent rocks.
How they are formed
Serozems are formed under the hydrothermal regime, which is characterized by a short spring period, warm and humid, in which the growth of vegetation and the action of microorganisms are activated. As well as a long dry and hot summer period, during which the bioactivity is greatly reduced.
One of the main characteristics of serozems is the active formation of humus and the mineralization of organic matter in the spring, intrasoil weathering of primary minerals, the accumulation of clay minerals in the upper and middle layers, a small content of soluble s alts, and a low content of humus.
How to use
Despite the small percentage of humus, the thickness of the humus horizon in gray soils is large - up to half a meter. Therefore, subject to irrigation, they are suitable for growing cotton, melons and vegetables, vineyards, corn, and beets. Measures to improve gray soils, except for irrigation: deep plowing and loosening, drainage.
Irrigated agriculture can greatly change the soil-forming processes on sierozem soils. Irrigation creates a new water regime, accompanied by the deposition of clay particles in the horizons.
The content of mineral elements necessary for plant nutrition in gray soils shows that the amount of nitrogen is insufficient, but it is in a form available to plants. Potassium and phosphorus are usually sufficient, often in this type of soil there is an excess amount of sulfates and chlorides.
On gray soils it is necessary to apply nitrogen, organic and mineral fertilizers, and to take measures to prevent salinization. Increases the fertility of gray soils by sowing green manure, for example, alfalfa.
Sierozem soils are found under a combination of certain climatic conditions of semi-deserts and such features as high spring activity of soil bacteria and animals, rapid growth and short vegetative period of semi-desert vegetation. Serozems, after improvement and subject to regular watering, are suitable for agricultural use for growing grapes, vegetables and cotton.
Recommended
Zheltozems and red soils: soil characteristics and humus content, use
Zholtozems and krasnozems are infertile acidic soils, the main characteristics of which place them in the category of unsuitable for growing crops.
Steppe soils: common types and their main properties, humus content
Location, climate, main types of steppe soils. Physical properties, soil formation processes, how steppe lands are used in agriculture.
Alluvial soils: characteristics and vegetation of floodplain soils, formation conditions
Under the alluvial types of soil understand the soils of the floodplain part of the rivers. They are often used for growing crops and as pastures for animals.
