Soil formation factors
The soil is a layer of earth covering the rocks of the earth. It plays an important role for various terrestrial ecosystems. The factors of soil formation are various plant and animal organisms, soil-forming rocks, relief, water, climate, age. Also, with the advent of humanity, its economic activity has become one of the main ones. Consider the factors of soil formation.
Soil-forming rocks are a nutrient medium in which the processes of soil formation take place, which include the numerous mineral components involved in soil formation. Approximately 60-90 percent of the total weight of the soil is minerals. The physical properties of the soil (the content of nutrients for plants, the speed of movement of substances in the soil, as well as its chemical and mineralogical composition) directly depend on the nature of the parent rocks.
The nature of the parent rocks quite strongly affects the type of soil. Soils of ash type can often be found in the conditions of the forest zone.Soils of the podzolic type can be formed in soil-forming rocks containing a large number of potassium carbonates. But if the soil-forming rocks contained a large amount of calcium carbonates, then the soils will have a significant difference from those of the podzol type.
Vegetation as a factor in soil formation
In the process of vital activity of various living organisms, plants, and also microorganisms, organic compounds are formed in the soil. The main role belongs to the vegetation. Green plants are the only creators of the very first organic substances. They absorb carbon dioxide from the atmosphere, and they take water and mineral substances from the soil, using solar energy, they form various not simple, energy-enriched, organic compounds. The highest content of organic matter in forest communities and the tropics, with high humidity. But the tundra, deserts and swampy places are deprived of organic matter.
When the plant dies out, both whole and its individual parts, organic matter enters the soil.Under the influence of animals, bacteria and various chemical and physical agents, decomposition occurs on the soil surface, with the further formation of humus. The mineral part of the soil is enriched with ash substances. The plant material, which has not yet had time to decompose, forms a protective litter. It is these formations that influence the gas exchange processes in the soil, the vital activity of microorganisms, the thermal regime of the uppermost soil layer, and the permeability of precipitation.
Vegetation can affect the structure and nature of organic matter in the soil, as well as its moisture regime. The degree of influence of vegetation on the nature and structure of organic substances on the composition and condition of plants, as well as on numerous other factors.
Animal organisms are designed to transform organic matter into soil. In the process of transformation, both aboveground and soil animal organisms are involved. The main function in the soil environment is given by the simplest and invertebrates. However, some vertebrates that spend a lot of time in the soil, such as moles, also play an important role. All soil animals can be divided into two groups: biophages and saprophages.The former feed exclusively on living organisms or their tissues, while the latter prefer organic matter.
The main amount of soil animals is represented by saprhaphy (earthworms). A large number of saprophages feed on the dead remnants of vegetation, and then throw their feces into the soil. If you trust the calculations of Darwin, then in a few years the entire soil mass passes through the digestive tract of the worms. Saprophages play a huge role in creating a soil profile and humus content.
Small rodents are numerous aboveground participants in the process of soil formation. Plant and animal residues that have fallen into the soil begin to participate in a rather complicated process of their change. Some of them decay to water, salts and carbon dioxide, and certain parts are converted into complex organic matter of the soil.
Microorganisms are the main factors of soil formation, they are calculated not even by thousands, but by billions per hectare of soil. They are diverse in composition and in their biological activity. These are various bacteria, fungi, viruses, unicellular algae and many others.They participate in the biological cycle of substances. With the help of microorganisms, decomposition of complex organic and mineral substances into simple substances takes place. Then simple substances are utilized either by the microorganisms themselves or by the plants. It is organic matter formed during the decomposition of plant and animal residues, called humus or humus.
Climate as a factor in soil formation
Climate is an important factor affecting soil formation. Only it depends on the biological and physical processes occurring in the soil. It affects the thermal and water regimes of the soil. Thermal regime is a combination of heat exchange processes between "the surface layer - the soil - the soil-forming nature." The heat regime is responsible for the processes of heat transfer and accumulation in the soil. The nature of the thermal regime can be determined based on the ratio of absorbed solar energy and thermal radiation of the soil. Character depends on the heat capacity, soil color, its moisture and other various factors. A great influence on the thermal regime has vegetation.
Basically, the water regime of the soil can be determined by the amount of precipitation and the process of their evaporation. In addition, there is a feature of their distribution throughout the year. Water, washing out the soil, has a significant impact on her and its composition.
Climatic conditions can affect soil-forming rocks, flora and fauna, and much more, but this effect is only indirect. Because only the distribution of the main soil types is associated with climatic conditions.
Relief as a factor in soil formation
Relief is a soil formation factor involved in the redistribution of heat and water over the surface of the earth. If there is a change in the height of the terrain, then there is also a change in the heat and water soil regimes. The clarity of the mountainous soil cover is determined by the relief. The relief also affects the nature of the influence of groundwater and rainwater on the soil and the migration of water-soluble substances.
Time as a factor in soil formation
Time is also an important factor in soil formation, because it is one of the most important processes in nature.The age of the soils of Western Siberia, North America, and Western Europe was determined using the radiocarbon method - from several hundred to several thousand years.