Alluvial soils: characteristics and vegetation of floodplain soils, formation conditions

Alluvial soils are understood as lands located in floodplains. They are formed by alluvial particles. Such soil is often used to grow valuable agricultural plants and is actively used as pasture for domestic animals. It is also suitable for haymaking. This is especially true for meadow parts located in the center of floodplain terraces.

Characterization of alluvial soils

Practically all rivers have floodplain valleys, on which alluvial soils are formed. River flows after some time can change the state of their own banks.

This process is accompanied by the constant application of unconsolidated fragments of alluvium. This term refers to deposits that include not only mineral particles of various sizes, but also contain fertile silt. Its structure includes fragments of plants and animal waste products.

The formation of alluvial soils is associated with the duration of flooding with water. It can be different:

1. No more than 1 week. This is a normal duration and does not cause plant death.
2. 7-14 days. This period does not pose a threat to perennials, but dangerous to annuals.
3. More than 2 weeks. Only moisture-resistant plants and herbs can survive such flooding.

The key process involved in the development of alluvial soils is considered to be the settling of special particles.They stimulate the rapid rise of the topsoil. Alluvial particles are systematically rejuvenated. As a consequence, the soil profile grows upward. This prevents the full formation of the soil.

Such soils have a layered structure. At the same time, the layers differ in the level of layering. After some time, they descend and are covered with new elements of alluvial deposits. This is the hallmark of these types of soil.

Varieties

The soil formation conditions of alluvial soils are closely related to the water regime.

Because they differ in composition, humus content, vegetation patterns and key agricultural characteristics:

1. Meadow soils form in the center of river floodplains. Their main characteristic is the surface layer of turf with roots and a heavy humus horizon.Under natural conditions, these types of soil are meadows on which cereal plants and forbs grow. They are characterized by the presence of parent rock in the form of layered gleyed deposits with peat fragments.
2. Near-channel zones of river valleys are usually characterized by the formation of soddy floodplain soil. It is distinguished by the presence of forests and herbs. The main share in the structure of such land falls on sand and undecomposed fragments of the vital activity of animals and plants. This type of soil is considered layered. It includes a minimum of humus and is distinguished by weak horizons.
3. Swampy alluvial soils include a lot of peat and silt. These components are also present in the surface layer. Such soils have a layered structure and composition. These characteristics are due to frequent flooding associated with depressions that are located below ocean level.
4. Forest alluvial soils are characterized by loose structure, light granulometric composition and low humus content. Such types of soil are of the soddy type. They contain a minimum of nutrients and humus. In addition, the substrate is characterized by pronounced acidity.
5. Saline soils are considered the most difficult in terms of agriculture. These types of soils are found in large numbers in Asia. At the same time, the composition and distribution of s alts can differ significantly.

Meadow soil types are divided into 2 varieties:

1. Laminated - include fragments of sand and sandy loam. They also contain plant roots. The structure of such earth is granular and lumpy. It is found in low swampy areas.
2. Primitive layered - differ in the upper sod layer 1-2 centimeters in size and a weakly expressed humus layer 3-5 centimeters thick. This is a fairly heavy loamy soil, which is considered infertile.

Influence of climate and groundwater

A distinctive feature of alluvial types of soil is periodic flooding.This process is called floodplain. It is not always observed annually, but should lead to the accumulation of new mineral material. Also, the formation of these types of soil is affected by the proximity of groundwater.

Where are they common?

Alluvial soil types are found in river floodplains. They are common in almost all soil and climatic zones of Russia. To a greater extent, such soil is found in the deltas and floodplains of the Oka, Don, Ob, Lena, Volga, Irtysh. Good conditions for the development of vegetation are considered a characteristic feature of these sites.

Features of use

The use of floodplain rivers in agriculture can be complicated by significant relief differences. Constant spills and floods in the spring necessarily flood the lowlands. That is why they have to be dried all the time. In addition, such areas are difficult to process.

Although alluvial soils have high potential, they are most often left as grasslands and only a small part is used for growing forage vegetables and cereals, which are resistant to moisture.

To use alluvial soil types for agricultural purposes, it is important to carry out a whole range of activities. They must include the following:

1. Weeding future arable land from weeds and cleaning from small debris, which is washed by the river flow and groundwater.
2. Nitrogen and phosphorus fertilization.
3. Liming acidic soil types after draining. For this, chemical reclamation is used. During the procedure, it is required to add calcite, belite or dolomite flour. To neutralize the soil, you can use lime tuff. Shale or peat ash is also used for this purpose.Defecates, which are waste products of sugar production, are also highly efficient.
4. Sowing seeds in the sod layer. This is required when using soils in animal husbandry. Thanks to this event, it is possible to significantly improve the structure of herbage.
5. Plowing heavily wetlands. It is carried out in case of degradation of meadows. This method is used to significantly improve floodplain lands.
6. Additional irrigation. This helps to subsequently grow vegetables and forage grasses in river floodplains. Also, these areas are suitable for fruit and berry plants.
7. Timely sowing and irrigation work. They are an important condition for the restoration of soils that contain little humus.
8. Use of potash fertilizers for sandy and sandy loamy soil types. Soddy soil needs nitrogen and humus.

Drained swampy lands require products that contain a lot of copper, potassium and organic matter. These substances contribute to the activation of microbiological processes and increase soil fertility.

Alluvial soils differ in structure and structure. This must be taken into account when using these types of soil for agricultural purposes.

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