Type is the main unit of soil classification. It stands out in accordance with the profile of the earth. VV Dokuchaev in 1886 for the first time classified types.
Soils that arose during the cultivation of plots not previously suitable for the development of agriculture belong to a special group.
Some species do not form groups (zones), are found in separate areas within the zones. This is largely due to the characteristics of the rocks, moisture, topography.
The most common are zonal soil types. They (together with plant and other landscape elements) form natural areas.
Soil types
- Swamp land. These soils form with prolonged or excessive constant moisture (swamping). As a rule, they are formed in forest areas of temperate zones.
- Brown forest. These types of soils are mainly found in coniferous-deciduous and broad-leaved forests in areas with a moderately warm humid climate.
- Brown semi-desert, desert-steppe. These types of soils are formed in areas with a dry climate, in the temperate zone, under desert-steppe plant species.
- Mountain. They are a group forming in the highlands. Almost all types of soils that fall into this category are characterized by graveliness, low thickness and the presence of primary minerals.
- Chestnut. Distributed in semi-deserts and steppes of the temperate zone.
- Meadow soils are formed under meadow plant species, in areas of high surface moisture or in areas subject to continuous groundwater.
- Saline. Distributed in arid areas with a high concentration (more than 0.25%) of mineral salts that are readily soluble in water - magnesium, calcium, sodium carbonates , sulfates, chlorides.
- Podzolic soils are formed in mixed forests and taiga, in a temperate continental and continental climate. They experience excessive moisture and are constantly washed with leaking water.
- Sierozems are common in deserts and semi-deserts in the subtropical zone.
- Merged soils are formed in the subtropical, tropical, equatorial zones. In their profile, they have a merged horizon, which in the wet state swells strongly and acquires high ductility, and remains dry and solid in the dry state.
- Tundra. A combination of soils of the Northern hemisphere, its tundra zone. This category includes tundra humus-carbonate, sod, podzolic and other soils.
- Chernozems. These soils are common in the steppe and forest-steppe zones of the temperate zone.
An important indicator in the classification of soil is its composition.
Light - sandy - soils include a large amount of sand, a small proportion of humus, a small amount of clay particles. Soils of higher density are classified as heavy - clay soils. They do not crumble during processing, on the contrary, form large clods, which makes digging very difficult.
Stony soils are common on the slopes of mountains or hills and are not fertile. Most of their composition is occupied by rock fragments.
The basis of peat-bog soils is largely organic matter. They are rich in nitrogen, contain little potassium and a very small amount of phosphorus. However, there are peat vivianite soils, in which, on the contrary, there is a high concentration of phosphorus.
Sandy loam soils are endowed with many sandy properties with a more balanced ratio of components; they belong to the intermediate variety. These soils are considered favorable in all respects for the cultivation of plants.