What factors affect the structure of the soil: the necessary conditions for the formation

Table Of Contents

Physical and chemical factors of structure formation
Physico-mechanical
Chemical
Biological

Soil is an independent natural body, which was formed as a result of the combined activity of various external forces. What factors influence soil structure? These include plant and animal organisms, the parent breed, the age of the country, relief, and climatic conditions. Also, the structure of the soil is affected by the economic activities of people.

Physical and chemical factors of structure formation

People are often interested in what conditions are necessary for the formation of soil. Physical and chemical factors play a significant role. Under natural conditions, the coagulation of clay-colloidal components that are present in the soil structure matters.They are reversible and irreversible. The second option provokes the formation of aggregates that are resistant to moisture.

Irreversible coagulation is associated with the influence of absorbed cations. These include calcium, iron, aluminum. Also important is the mutual coagulation of soil colloids, which differ in positive and negative charges.

For example, colloidal compounds of aluminum and iron, as well as silica and humus, due to mutual coagulation form strong coagels. Also, irreversible coagulation can occur during freezing, thawing, drying of soil hydrogels with irreversible loss of moisture. This process is accompanied by gradual crystallization.

In this case, coagulation is also reversible. For example, coagulation of soil colloids and clays, associated with an increased content of potassium and sodium s alts, provokes the formation of structural aggregates. However, they are not very resistant to water.

The reversibility of coagulation provokes the dispersion of colloids that have previously coagulated. If, during land irrigation, the environment becomes more alkaline, and exchangeable calcium is replaced by sodium, structural aggregates in the soil disintegrate. This is due to the dispersion of the colloidal material.

Physical and chemical factors of soil formation are due to the presence of organic and mineral colloids in the composition. At the same time, organic matter is considered the most significant - in particular, humus.

Physico-mechanical

Among this group of factors, pressure plays a significant role. The development of the root system, the movement of insects and animals, as well as the creation of chambers and holes by them, leads to the appearance of pressure on the ground fine earth.This entails its aggregation. The swelling and expansion of the soil when wet has the same effect.

Further drying of the soil mass leads to a reduction in volume, the appearance of cracks, and the occurrence of increased intracapillary pressure. The alternating swelling and contraction of the soil mass is considered one of the important mechanical factors in soil formation. Freezing of ground water with an increase in volume and pressure has a similar effect. It is replaced by melting ice and a decrease in pressure.

Chemical

During soil formation and weathering, new chemicals are produced that transform into an insoluble form. This can result in a water-resistant ground structure. For example, the accumulation of iron, magnesium, and calcium carbonate silicates in the soil leads to cementation of primary mechanical substances and their gluing.This causes water-resistant aggregates to form.

Biological

Biological and biochemical factors are important for soil formation. The structure of soils and their water resistance are closely related to the accumulation of humus and the functions that microorganisms perform. The active formation of the soil is due to the constant vital activity of bacterial microorganisms and fungi.