Sod-calcareous soils: characteristics and properties, structure and use

One of the rather rare types of soils - sod-calcareous. They are only found in certain areas. Let us consider how such soils are formed, under what conditions, their types (soddy-calcareous, soddy-lithogenic, soddy-gley) and properties. Where sod-calcareous soils are common, how and where they are used in agriculture.

How do soddy soils form?

The parent rock for these soils is carbonate, shallow. Soils of this type are formed under automorphic conditions and under leaching water conditions. Due to the large amount of calcium in the rock, organic acids undergo neutralization and are converted into humates, which accumulate in the upper humus layer.Due to such conditions, the fertile layer is colored dark, has a neutral reaction, a clearly visible granular structure.

There is quite a lot of humus in soddy-calcareous soils - 5-7%. Such soils are divided into 3 subtypes, with different morphological profiles - these are typical soils, leached and podzolized. Soddy soils are formed by herbaceous vegetation covering meadows or sparse forests with a grassy surface.

Properties and types

Soddy soils are divided into types, their differences are in different forming rock, structure, conditions of soil formation.

Sod-carbonate

These are soils that form in the southern taiga under coniferous and mixed forests, on carbonate rocks. Formation requires excess moisture. The podzolic layer is not formed, because calcium neutralizes the acid formed after the decay of plant residues.

Sod-calcareous lands are created on the eluvium of marls, dolomites and limestones. They are divided into subtypes: typical and leached. A soddy horizon protrudes in the profile of typical soils; it has a finely cloddy or granular structure. Organics are fixed in the upper horizon and stain the layer in a dark gray color. The thickness of the fertile layer is approximately 10-15 cm.

Below it is a gray-brown transition layer, which is enriched with limestone fragments. Beneath it lies the bedrock. One of the main characteristics is fertility. Humus is contained in the soil at the level of 15-20%. The reaction is neutral or slightly alkaline.

Sod-lithogenic

Formed in drained areas, in areas covered with coniferous and deciduous-coniferous forests, with shrubs and grassy cover.They are formed on the eluvium of parent rocks, their properties and composition interfere with the process of podzol formation, and therefore it does not occur. Podzol does not form on rocks that are rich in magnesium and calcium silicates, they are released during weathering and neutralize acidity.

Also, podzol is not formed or weakly formed on the eluvium of rocks that are rich in iron, and on shales. In the process of development of the soddy-lithogenic type of land, as the amount of unweathered mass decreases, the degree of influence of the rock on the processes of soil formation is weakened, and the podzolic process begins in it. Morphologically, this is expressed in a whitish silica powder that appears at the bottom of the humus horizon and directly below it.

Gley Sod

The profile of soils of this type consists of litter, the thickness of which depends on the intensity of moisture. Then comes the humus layer, gray or steel-gray in color, with a granular structure if the earth is formed on loam.

Transition layer dirty-brown with rusty smudges and veins, usually with hard concretions, in all cases gleyed, the degree of this process is different. Gleying does not appear over the entire horizon, but from above, with surface moisture, or below, with ground moisture.

The structure when forming on loam is granular or cheesy. The lower horizon is a parent rock that may or may not be gleyed.

For sod-gley soils, a high content of humus, organic matter and humic acids, which are associated with calcium, is inherent. The reaction of soddy-gley soils is slightly alkaline or neutral.

Develop under coniferous and mixed forests with grass cover, on poorly drained plains, areas with carbonate rocks, on lowlands with temporary stagnant moisture or relatively high levels of hard groundwater.Can form under meadow vegetation.

Distribution

Sod-calcareous soils are located locally in small areas across Europe. Most of these soils are in Poland and Belarus, in Transbaikalia.

Where is it used?

Sod-calcareous soils, if favorable conditions are created, can provide large yields of grain crops, despite the short growing season, a small amount of active temperatures, shallow snow cover, lack of precipitation. Grain crops are placed on warmed relief areas with good moisture conditions.

Sod-calcareous soils are located fragmentarily among the brown soils of the forest zone. They are located on the territory, which is composed of rocks containing dolomite, limestone, marble, marls and clays. They form under broad-leaved forests, mainly oak and oak-beech.Due to the fact that the soils are formed on calcium rocks, the acidity is neutralized, and they do not turn into podzolic. Organic matter binds to calcium and remains in the top layer of the profile. For this reason, such soils have a well-defined humus horizon rich in absorbed s alts. Therefore, they are of value for growing plants, provided that agrotechnical work is carried out to maintain their fertility.