Soil structure
Such a fundamental characteristic of the soil as a structure depends primarily on its composition and humus content, which in turn determines the degree of activity of the soil fauna, the ability of the soil to absorb, retain moisture and form a strong capillary system that delivers water from the lower layerssoil to the upper, its heat exchange and air permeability. The soil structure is understood to mean the spatial ordering of solid
soil particles and spaces between them - pores. Ideally, the soil should consist of 50 % from solid particles of soil material and 50% of closed or networked voids filled with air and water.
Most of the soil mass consists of mineral particles, up to 10% of the soil composition is organic substances such as humus and numerous soil organisms that live in it, the rest being caverns between the solid particles of the soil, filled with soil moisture and air. The accepted classification of soil types is based on the percentage content of mineral and organic parts in them. Thus, sand, which is the basis of sandy soils and largely included in the composition of loamy soils, is formed from grains ranging from 0.05 to 2 mm. Such a sufficiently large structure of soil solids causes the formation of vast spaces between them and determines such soil qualities as high air and water permeability and rapid warming-up.
Clay particles, on the contrary, do not exceed 0.003 mm in size and fill the entire physical space of the soil, forming a very dense structure with a small number of empty spaces. Therefore, clay soils are characterized by low air and water permeability, slow warming-up, and a tendency to stagnant processes.
A dense, or monolithic, soil structure characterized by heavy soils with an increased clay content is not very favorable for plants. It poorly passes water and air, prevents growth and free placement of roots. Due to insufficient air and water supply of such soil, the biological activity of microorganisms is limited in it, which means that the level of the products of their vital activity and nutrients is reduced. Especially strongly the cohesive structure of the soil is manifested after the moisture has fallen on it, when the dissolved clay particles fill the whole space, forming the so-called concrete soil.
Sandy, or, worse, is a pulverized, soil structure is also unfavorable for plants. Due to their excessive flowability, solid soil particles do not form lumps, water is quickly absorbed and is not retained by the soil, leaving in the lower layers and not: restraining in the soil layer. Water carries with the oboe dissolved nutrients, some plants simply do not have time to digest and therefore suffer from a lack of water and nutrients. Plants do not take root in such soils, because the root system is not retained in a loose structure. Sandy and dusty soils quickly warm up and cool quickly, as there is no moisture, which can regulate the temperature regime and maintain the temperature balance of the soil.
Method of phytoindication of soil
The predominance of certain vegetation on certain sites allows one to draw conclusions about the structure, condition of the soil and its properties. Thus, by analyzing the vegetation in the area of the soil, we can approximately determine what type of soil we are dealing with. If the vegetative cover on a site of a soil is rare, it testifies to low natural fertility. High dense vegetation, consisting of strong healthy and externally strong plants, speaks of the good condition of the soil, its saturation with nutrients. The predominance in the plant cover of moisture-loving plants indicates a close occurrence of groundwater.
Soils with high nitrogen content - nettle nettle, sow, mint, common cross.
Soils with low nitrogen content - field clover, lapwing, pinworm, linen.
Mortgaged soils - camomile chamomile, shepherd's bag.
Sealed soils - plantain large, goatee goose, foxtail.
Humus soils - middle stellate, Veronica field, purpurea purple, dandelion, officinalis, carrot.
Overmoistened and waterlogged soils - moisture-loving vegetation, sedge, horsetail, pikul-nik, pike, cane.
The most favorable for all plant species is the fine-grained, or grainy soil structure, where individual solid soil particles form lumps up to 8-10 mm in diameter. Due to the presence of sufficient spaces between individual lumps, such soil is characterized by good water permeability, the ability to absorb, accumulate moisture, form a strong capillary system, supplying moisture to the plant roots, as well as excellent air permeability and rapid warming of the sun's rays. The loose loose structure of the soil depends on the clayey-humus combination of its various constituents that arise as a result of the vital activity of numerous soil organisms mixing
. The size of solid soil particles depends on the soil structure and its basic properties
of the mineral and organic parts of the soil and "gluing" them togetherthe process of assimilation by microorganisms, bacteria and other representatives of the biological environment of the soil. Ultimately, the goal of any processing process is to achieve a loose soil structure while preserving its complex composition.
An important mechanical indicator of the soil condition is its density, which is simply determined experimentally for any forms of machining. The increased density of is characterized by some types of solonetz soils, it is almost impossible to dig a shovel, tools are needed that break their structure, such as scrap, pick, spade. Heavy soils are difficult to process, a considerable effort is required to dig a shovel and break up strata and clods. Clay soils and lower horizons of loamy soils are usually dense. Friable soils are easy to process, they are excavated with a shovel with minimal effort, the selected strata of the earth themselves collapse into lumps and smaller structural lumps. Such a density is usually possessed by humus and well-cultivated soils.
Loose soils represent a certain difficulty for processing, as when excavating a pit or a trench, edges and walls fall off, and formlessness arises. Such a friable mass of soil is characteristic of sandy loamy soils.
So important is the soil structure, such as soil sorption. Over 80 % of precipitated precipitation falls during infiltration into the soil in order to absorb these huge natural amounts of water, the soil must fully fulfill the filtering and water-accumulating functions, that is, it has good sorption.
Under soil sorption is the ability of the soil to absorb moisture from the environment, accumulate and retain it, and to delay and bind nutrients, trace elements, salts and other substances in its composition. In this case, we can talk about physically and biologically related substances.
From the sorption of soil depends and its characteristics, such as moisture capacity. The degree of moisture capacity indicates how much rainfall can be absorbed, digested and later used by the soil, and which will prove to be excessive. Excessive rainfall, not assimilated by soil, drains over its surface and erodes the arable layer. Thus, the longevity of the integrity of the soil cover depends on the moisture content. The best sorption capacity and moisture capacity are characterized by soils with a sufficiently loose porous grains, a hundred-cloddy structure capable of retaining water-soluble nutrients and transforming them in the process of full metabolism into a form acceptable for plant assimilation. Sandy soils do not have good sorption, and valuable nutrients are washed away, leaving deep layers of soil inaccessible to plant roots, leaving with water. In clay soils, on the other hand, any movement of accumulated moisture with nutrients dissolved in it is extremely limited, so plant nutrition and the metabolism process are difficult.
To the roots of plants, moisture comes from a process, reverse infiltration, or absorption of moisture. During this process, water from the soil thickness moves towards the surface through a system of thin hair vessels - capillaries, and the process itself is called capillary rise of water. Rising to the top layers of the soil, moisture enters the root system of plants, and partially evaporates from the soil surface. The capillarity of the soil also depends on its structure. On sandy soils, the capillary ascent through the horizon of groundwaters first proceeds quickly, but reaches only a small height in comparison with clay soils with a slow process and a higher rise. An important characteristic of the soil is its ability to absorb solar heat from the . This affects the thermal regime of the soil as a whole, which affects the development of plants, which occurs under certain conditions of the temperature regime. Changes in the temperature regime of the soil in the direction of increasing or decreasing may adversely affect the germination of seeds and the subsequent development of plants. The ability of the soil to absorb heat is influenced by a number of factors:
Soil texture structure: The more in large soil( sand) soil, the faster it heats up and the less heat it takes to reach a certain temperature index;
Soil color: Dark soils better accumulate heat, as the darker surface heats up faster, in the spring the dark soils quickly thaw;
moisture content in the soil: , dry soils heat much faster than wet soils, the degree of soil warming is also higher;
degree of soil saturation with humus and other organic substances: humus soils warm up better and faster due to dark color, loose porous structure providing thermal conductivity, and optimum moisture content in soil composition.
It should be remembered that the soil structure can be largely adjusted, modified and, at times, radically improved.
Soil analysis
Before taking any measures to improve the soil structure, its chemical composition, to enrich it with nutrients
Soil selection rules for the
sample. On the plot area of 15 - , 20 places to make the
pit ki depth to the pins. Scoops scraped
in substances, it is necessary to make soil analysis, so that any actions are purposeful.
Soil analysis will reveal its composition, the level of the content of various chemical elements and compounds, a set of mineral substances, the degree of humus content, the acid reaction of the soil and many other parameters.