Soil - its properties, composition, absorption capacity

Soil - its properties, composition, absorption capacity

About soil, elements and plants "for health". Part 2

Read the previous part: On the "usefulness" of vegetables, as a derivative of soil quality


To prevent depletion of the soil, to obtain vegetables on it with a full-fledged content of nutrients, it is necessary to apply fertilizers, including mineral fertilizers, and the use of chelated micronutrients.

It has been established that plants have critical periods in relation to a particular mineral element, that is, there are periods of higher plant sensitivity to a lack of this element at certain stages of ontogenesis. This allows you to adjust the ratio of nutrients depending on the phase of development and environmental conditions.

With the help of fertilizers, it is possible to regulate not only the size of the crop, but also its quality. So, to obtain wheat grain with a high protein content, nitrogen fertilizers must be applied, and to obtain products with a high starch content (for example, malting barley grains or potato tubers), phosphorus and potassium are needed.

Foliar feeding with phosphorus shortly before harvesting enhances the outflow of assimilates from the leaves of sugar beet to root crops and thereby increases its sugar content. Thus, with the right approach mineral fertilizers we need.

Let's take an example from practice. Let's calculate the required amounts of nutrients, say, for tomato... With a planned yield of 50 kg from 10 m², this plant carries out 225–250 g of nitrogen, 100–125 g of phosphorus and 250–275 g of potassium. According to the results of agrochemical analysis in the field where they plan to grow tomatoes next year, it turns out before fertilizing that in the arable soil layer (0-30 cm) on 10 m² there are about 150 g of nitrogen, 20 - phosphorus and 200 g of potassium in digestible forms ...

Consequently, in order to obtain the planned yield, it is necessary to add 75–90 g of nitrogen, 80–100 g of phosphorus and 25–50 g of potassium to this area. Ultimately, about 250-300 g of ammonium nitrate, 400-500 g of simple superphosphate and no more than 100 potassium salt per 10 m² should be added to the tuk. Doses organic fertilizers are determined taking into account the content of the main elements in them. For example, take manure, but you can use a good compost... It is known that 150 g of nitrogen, 75 - phosphorus, 180 - potassium, 60 - manganese, 0.0010 g - boron, 0.06 - copper, 12 - molybdenum, 6 - cobalt, about 0 , 5 g of calcium and magnesium (in terms of carbon dioxide).

That is, when applying 30 kg of litter manure per 10 m² of tomato beds, the crop's need for basic nutrients is almost completely covered. However, taking into account the fact that manure supplies the soil-absorbing complex with the main elements of plant nutrition for three years, along with organic fertilizer, adjusted doses of mineral fertilizers are also introduced, i.e. mineral fertilizers are required much less when applied together with organic matter.

The advantage of organic fertilization consists in a positive effect on the agrophysical properties of the soil (the micro-aggregate composition and water resistance of the macro- and microstructure improve, the water-holding capacity, the content of available soil moisture, the rate of infiltration, porosity, etc.). With the introduction of the said rate of manure, 1.6-1.7 kg of humus is formed. It should be noted that the amount of humus formed will vary depending on the soil cover and the quality of the manure.

The removal of nutrients from the soil with the harvest must be compensated for by the appropriate introduction of organic and mineral substances, otherwise we worsen the fertility of the soil. It is clear that in summer cottages, where there is not much cultivated land, the consumption of fertilizers is small, which means that it is quite possible to find several buckets of good humus. 10 m2 30 kg is required, but 10 hectares will require 300 tons of manure and, accordingly, 3 tons of mineral fertilizers.

In Poland, for example, in large areas they use green manure, plan sowing peas, lupine, wiki, seradella, ranks, clover, mustard and other plants, the green mass of which is plowed into the soil. Decomposing, this material will improve the water-physical properties of the soil, enrich it with beneficial microflora and nutrients. Indeed, in terms of nutritional value, green manures are close to manure.

Green manure crops are sown in spring, and then, having plowed them into the soil, late vegetable plants are placed there, potatoes... They are also sown as re-crops after early vegetables, in wide aisles of row crops, etc. It should be noted that green manure enriches the soil mainly with nitrogen, and therefore phosphorus and potassium fertilizers are added to them in optimal doses for the culture grown.

To obtain a good green manure mass in dry periods, the soil is watered (400–450 m² / ha). The number of waterings can vary between 3-5. In general, mineral fertilizers in the form of dressings are indispensable for correcting plant growth in its various phases. The effect of organic fertilizers strongly depends on the biological activity of the soil, and in the North-West, especially in spring when the temperature drops, mineral nitrogen fertilization is necessary, fertilizing with microelements for many crops.

Let's try, from the point of view of modern genetic soil science, to understand the methods of farming. In his work "Lectures on Soil Science" (1901) V.V. Dokuchaev wrote that the soil "... is a function (result) of the parent rock (soil), climate and organisms, multiplied by time."

One way or another, in the words of Academician V.I. Vernadsky, the soil is the bioinert body of nature, i.e. soil is a consequence of life and at the same time a condition for its existence. The special position of the soil is determined by the fact that both mineral and organic substances are involved in its composition and, which is especially important, a large group of specific organic and organomineral compounds - soil humus.

Greek philosophers, starting with Hesiod and up to Theophrastus and Eratosthenes, tried for six centuries to comprehend the essence of soil as a natural phenomenon. Roman scientists were more inclined to practicality and over the course of two centuries created a fairly harmonious system of knowledge about soils and their agricultural use, fertility, classification, processing, fertilization.

I will not go deeply into the theory of soil science, I will note that interest in the study of soil, as you understand, has been manifested by humanity since ancient times and, as we decided, in order to obtain useful vegetables and other plants, we need a soil in which plants can find everything. substances necessary for their development.

With the accumulation of information about the soil and the development of natural science and agronomy, the idea of ​​what determines soil fertility also changed. In ancient times, it was explained by the presence in the soil of special "fat" or "vegetable oils", "salts" that give rise to all "plant and animal" on Earth, then - by the presence in the soil of water, humus (humus) or mineral nutrients, and finally , soil fertility began to be associated with the totality of soil properties in the understanding of genetic soil science.

Only in the 19th century, primarily thanks to the works of Liebig, was it possible to eliminate erroneous ideas about plant nutrition. For the first time, two German botanists F. Knop and J. Sachs succeeded in bringing a plant from seeds to flowering and new seeds on an artificial solution in 1856. This made it possible to find out exactly what chemical elements plants need. Soil fertility is understood as its ability to ensure the growth and reproduction of plants with all the conditions they need (and not just water and nutrients).

The same soil can be fertile for some plants and little or completely barren for others. Swamp soils, for example, are highly fertile in relation to swamp plants. But steppe or other plant species cannot grow on them. Acid, low-humus podzols are fertile in relation to forest vegetation, etc. The elements of soil fertility include the entire complex of physical, biological and chemical properties of the soil. Of these, the most important, determining a number of subordinate properties, are as follows.

Granulometric composition of the soil, i.e. the content of fractions of sand, dust and clay in it. Light sandy and sandy soils warm up earlier than heavy ones, and they are referred to as "warm" soils. The low moisture capacity of soils of this composition prevents the accumulation of moisture in them and leads to the leaching of soil nutrients and fertilizers.

Heavy loamy and clayey soils, on the contrary, take longer to warm up, they are "cold", since their thin pores are filled not with air, but with very warm water. They are poorly water and air permeable, poorly absorb atmospheric precipitation. A significant part of soil moisture and reserves of nutrients in heavy soils are inaccessible to plants. Loamy soils are the best for the growth of most cultivated plants.

The content of organic matter in the soil. The quantitative and qualitative composition of organic matter is associated with the formation of a water-resistant structure and the formation of water-physical and technological properties of the soil favorable for plants. Biological activity of the soil. The biological activity of the soil is associated with the formation of microbial products in it, stimulating the growth of plants, or, conversely, exerting toxic effects on them. The biological activity of the soil determines the fixation of atmospheric nitrogen and the formation of carbon dioxide, which is involved in the process of plant photosynthesis.

Soil absorption capacity. It determines a number of soil properties vital for plants - its nutritional regime, chemical and physical properties. Due to this ability, nutrients are retained by the soil and are less washed out by precipitation, while remaining easily accessible to plants. The composition of the absorbed cations determines the reaction of the soil, its dispersion, the ability to aggregate and the resistance of the absorbing complex to the destructive action of water in the process of soil formation.

The saturation of the absorbing complex with calcium, on the contrary, provides plants with a favorable, close to neutral reaction of the soil, protects its absorbing complex from destruction, promotes aggregation of the soil and the fixation of humus in it. That is why it is so important to carry out liming of the soil on time. Thus, practically all physical, chemical and biological properties of soils serve as elements of soil fertility.

Read the next part. Soil types, mechanical processing, fertilizers and fertilizing →

Vladimir Stepanov, Doctor of Biological Sciences


Relief

This factor has an indirect effect on the process of soil formation. The relief determines the law of moisture and heat redistribution. Depending on the altitude, the temperature regime changes. It is with the height that the vertical zoning in the mountainous regions of the planet is associated.

The nature of the relief determines the degree of climate impact on soil formation. Redistribution of precipitation occurs due to elevation changes. In low-lying areas, moisture accumulates, but on slopes and hills it does not linger. The southern slopes in the northern hemisphere receive more heat than the northern ones.


The concept of the composition of an object of landscape architecture on the example of well-known parks

49. The concept of volumetric-spatial structure. Types of spatial structures (SPT) are a characteristic of each type. Optimal ratio of types of spatial structures

VOLUME-SPATIAL STRUCTURE: this is a category of composition, reflecting the semantic connection, subordination and interaction of all elements of the form with each other and with space.

The concept of the volumetric-spatial structure of an object of landscape architecture includes the space (territory) of the object and its constituent plane (surface of the earth) and volume (plantings and structures). When organizing this structure, functional, aesthetic and biological-ecological problems must be solved.

Determination of the type of spatial structure, the ratio of which forms the volumetric-spatial structure of landscape architecture objects is an important task in the design.

Types of spatial structures (SPT) - characteristics of each type

1. open type of spatial structure is a space of a lawn, paths and areas, flower beds with a single arrangement of shrubs and small trees, the projection area of ​​the crowns of which does not exceed 10-15% of the site.

2. Semi-open TPN are plantations in the form of small groups or row plantings of woody plants, with crown projections, occupying up to 50% of the area of ​​the site. Closeness 0.3-0.5

3. A closed type of spatial structure is formed by uniformly closed plantings, projections, the crowns of which occupy almost the entire area of ​​the boulevard site. Closure of the canopy 0.6-1.

The volumetric-spatial structure of plantings under the influence of anthropogenic loads and other factors is destroyed, plantings cease to perform their functions (aesthetic, ecological-biological and microclimatic).

zone closed half-open open
forest 20-25 25-30
forest-steppe 55-60 25-30 15-20
steppe 65-70 20-25 10-15

50. Soil, its basic properties. Types of fertility, ways to increase it.

Soil is the surface layer of the Earth's lithosphere, which has fertility and is a multifunctional heterogeneous open four-phase (solid, liquid, gaseous phases and living organisms) structural system formed as a result of weathering of rocks and the life of organisms. It is considered as a special natural membrane (biogeomembrane) that regulates the interaction between the biosphere, hydrosphere and the Earth's atmosphere. Soils are formed under the influence of climate, relief, the original parent rock, as well as living organisms and change over time.

Structurality of soils is the ability of the soil mass to disintegrate into separate lumps of various shapes and sizes. On virgin soil, each soil type is characterized by a specific structure.

A soil property is a stable soil characteristic that determines its functioning and development.

Basic soil properties:

- Mechanical absorption capacity - the property of soil to mechanically retain substances suspended in water, is due to the mechanical composition, structure, composition, porosity and capillarity of the soil.

- Physical absorption capacity - the property of soil to absorb electrolyte molecules from solution, products of hydrolytic decomposition of salts of weak acids and strong bases, as well as colloids during their coagulation.

- Chemical absorption capacity - the property of the soil to retain ions as a result of the formation of insoluble or hardly soluble salts.

- Biological absorption capacity is associated with the vital activity of soil organisms (mainly microflora), which assimilate and fix various substances in their body, and when they die off, they enrich the soil with them.

- Physical and chemical properties of soil:

Physical include: porosity, plasticity, stickiness, cohesion, hardness

To Chemical soil buffering - the ability of a soil suspension to resist a change in its active reaction (pH) when acids or alkalis are introduced into the soil.

- Thermal properties and thermal regime of soils - The ability to absorb radiant energy, which turns into heat.

- The water properties of the soil are an important factor in soil formation

The most important property of the soil is its fertility, i.e., the ability to ensure the growth and development of plants. To be fertile, the soil must have a sufficient amount of nutrients and a supply of water necessary to feed the plants, it is by its fertility that the soil, as a natural body, differs from all other natural bodies (for example, barren stone), which are not able to provide the need of plants for the simultaneous and the joint presence of two factors of their existence - water and minerals.

Distinguish the following types of fertility: natural (natural), artificial, potential, effective and economic.

Natural (natural) fertility is the fertility that the soil (landscape) possesses in its natural state. It is characterized by the productivity of natural phytocenoses.



Artificial fertility (natural-anthropogenic, according to V.D.Mukha) is the fertility that the soil (agricultural landscape) possesses as a result of human economic activity. In many respects, it inherits the natural one. In its pure form, it is typical for greenhouse soils, reclaimed (bulk) soils.

The soil has certain reserves of nutrients (reserve fund), which are realized when creating a crop of plants by partial consumption (exchange fund). From this view, the concept of potential fertility follows.

Potential fertility is the ability of soils (landscapes and agricultural landscapes) to provide a certain yield or productivity of natural cenoses. This ability is not always realized, which may be associated with weather conditions, economic activity. Potential fertility is characterized by the composition, properties and regimes of soils. For example, chernozem soils have high potential fertility, podzolic soils have low potential, however, in dry years, crop yields on chernozems may be lower than on podzolic soils.

Effective fertility is a part of the potential, realized in the yield of agricultural crops under certain climatic (weather) and agrotechnical conditions. Effective fertility is measured by the yield and depends both on the properties of the soil, landscape, and on the economic activity of a person, the type and variety of crops grown.

Economic fertility is effective fertility, measured in economic terms that take into account the value of the crop and the cost of obtaining it.

Measures to improve soil fertility:

- ensuring an increase in the content of nutrients and humus in the soil

- Improvement of the phytosanitary state of arable and reclamation - previously drained and irrigated lands

- rational use of eroded land

- Prevention of the development of soil degradation processes.

Biological ways of hanging soil fertility

Vermicompost is a microbiological fertilizer containing microorganisms. Which, when they enter the soil, populate it, secrete phytohormones, antibiotics, fungicidal, bactericidal compounds, which leads to the displacement of pathogenic microflora. All this heals the soil, eliminates many plant diseases, and increases soil fertility.

Peat, agromeliorates (sawdust, finely chopped branches), compost, green manure (cereals or legumes used as fertilizers)

Date Added: 2015-04-18 Views: 22 Copyright Infringement


Chapter 3 AGROCHEMISTRY AND SOIL FERTILITY

Soil fertility is the ability of the soil to meet the needs of plants for nutrients, moisture and air, as well as to provide conditions for their normal life.

Soil is the source of material well-being for mankind, the greatest gift of nature. Therefore, the protection and reproduction of soil fertility is the fundamental principle of highly productive agriculture, obtaining high and sustainable yields. An important indicator of high soil fertility is the presence of a sufficient supply of nutrients necessary for plants, which are in a form available for crops due to the mobilization of elements that make up potential fertility and the use of fertilizers.

An important property of the soil is its absorption capacity, which is understood as the ability of the soil to absorb and retain solid, liquid and gaseous substances.

Due to the absorption capacity of the soil, nutrients, while remaining available to plant roots, are kept from leaching. They accumulate in the soil for centuries, participate in biochemical cycles, ensuring the life of new generations of plant organisms. High soil fertility provides optimal plant nutrition, the formation of a high yield and high-quality products for human nutrition and animal feed. Such soils are able to accumulate moisture in the required quantities and forms and keep it from seeping along the profile, washing off along the surface and evaporating into the atmosphere, creating optimal water and air conditions. Good humus and structural condition of the soil ensures its high moisture capacity.

An important property of fertile soils is their biological activity, which characterizes the intensity of biological processes in the soil. The beneficial microfauna of the soil not only takes part in the biological cycle of nutrients, but also releases enzymes, antibiotics, growth stimulants and other organic substances that have a beneficial effect on cultivated plants.

The creation of optimal conditions for the growth and development of plants is largely associated with a change in the physical, chemical and biological properties of the soil, the presence in it of a sufficient amount of nutrients assimilable for plants, the intensity of the processes of the transition of nutrients from a form that is difficult for plants to an easily accessible form and vice versa, i.e. processes of their mobilization and immobilization. All this determines the need of cultivated plants in fertilizers, as well as in the use of a complex of agrotechnical and reclamation measures. In other words, there is a constant relationship between plants, soil and fertilizers.

The fertilizer introduced into the soil as a result of interaction with the soil and the effect of soil microorganisms undergoes various transformations that affect its ability to move in the soil, the solubility of the food elements it contains and their availability to plants. These transformations depend on the properties of the soil and fertilizers. For example, on sandy soils, the decomposition rate of incoming organic fertilizers, with the remaining factors being equal, is higher than on loamy and clayey soils.

The rate and degree of decomposition of organic fertilizers also depend on the enrichment of soils with microorganisms, their composition and biological activity, as well as on the conditions that determine the vital activity of microorganisms (soil composition, its structure and aeration, hydrothermal regime and physicochemical properties, on the presence of nutrients in it etc.). The intensity of mineralization of organic fertilizers is largely determined by their biogenicity. For example, manure is a biologically active substance, it is rich in microorganisms, each ton of it contains up to 13 kg of live microbes. Peat, on the contrary, is poor in microorganisms and therefore decomposes slowly in the soil.

In the soil, mineral fertilizers (like the mineral decomposition products of organic fertilizers) undergo profound transformations. For example, phosphate rock, under the influence of the acidic reaction of the soil solution or acidic secretions of the root system of a culture such as lupine, goes into a soluble form for plant nutrition. Mineral fertilizers can enter into exchange reactions with solid colloidal soil particles and thus be retained in it, can be absorbed by microorganisms and temporarily fixed in living plasma, etc. Speed

the processes of transformation of fertilizers received into the soil depends on the nature of fertilizers, soil properties, climatic conditions, as well as a set of agrotechnical measures. The interaction of fertilizers and soil can have positive or negative consequences in plant nutrition, yield formation and product quality.

In addition, fertilizer also acts on the soil (solution reaction, intensity and direction of microbiological processes, etc.), i.e. In addition to supplying the plant with food elements, fertilizers act on the general conditions of soil fertility. Therefore, it is very important to know the composition of the soil, its properties and fertility, the nature and direction of the physical, chemical, chemical and biological processes occurring in it. This will make it possible to correctly determine the features of the transformation of fertilizers in the soil and their effect on plant growth, taking into account the biological requirements and specific cultivation conditions.

The greatest effect from fertilizers is obtained in such conditions when plants are provided with all the necessary living conditions for them in the best possible way - food, water, air, heat, light, when the soil is clean of weeds, when plants are not affected by pests, diseases, etc.

For a more complete understanding of the influence of agrochemistry on soil fertility and properties, it is necessary to consider the following questions:

  • composition and properties of the mineral and organic parts of the soil
  • absorption capacity and soil properties
  • change and optimization of soil fertility and properties with prolonged use of fertilizers
  • biological circulation and balance of biogenic elements and humus in the agrocenosis.


Use of additives

To make the land in which the plants are grown to be as useful and safe for them as possible, the following additives are used:

  • Makes the soil light, loose, breathable.
  • Creates an acidic environment, pulling back limescale.
  • No bacteria.

Lowland (dark)

You can adjust the amount of additives used at your discretion. You can use our soil recipes as recommendations.

Even the best soil will not help a violet grow well if you water it. How to properly water a violet? Find out in the material on our link.


How to increase soil acidity

Before starting to oxidize the soil in the garden, it is necessary to find out its mechanical composition. The method that will need to be used to increase acidity will directly depend on the composition of the soil.

The first method is great for fairly loose soil. In this case, the best way is to add a lot of organic matter to the soil. The best organic remedies are compost, manure, or sphagnum moss. As the humus process takes place, your soil pH will begin to drop significantly to make the process more effective and noticeable. A large amount of organic matter will be needed.

The second method is suitable exclusively for dense and heavy soil, such soil is generally called clayey. In this case, you will need a lot of time and much more energy to increase the acidity. If you decide to use the first option with such soil, then nothing good should be expected. Since with the help of organic compounds you will only raise the alkaline level of the soil.


The structure, composition and properties of the lithosphere.

Lithosphere - the upper solid shell of the Earth, gradually turning into spheres with a lower strength of matter and including the earth's crust and the upper mantle of the Earth. The lithosphere is the most important part of the natural environment, characterized by area, relief, soil cover, vegetation, mineral resources, as well as space for all sectors of the national economy. The state of the lithosphere changes over time under the influence of natural forces and human activities.

One of the most important properties of the soil is its fertility, i.e. the ability to provide organic and mineral nutrition to plants. Fertility depends on the physical and chemical properties of the soil.

Soil is a three-phase medium containing solid, liquid and gaseous components. It is formed as a result of complex interactions of climate, plants, animals, microorganisms and is considered as a bioinert body containing living and nonliving components. As a result of the movement and transformation of substances, the soil is divided into separate layers, or horizons. The ratio and extent of the horizons in depth depends on the type of soil; the uppermost horizon, which contains the products of decomposition of organic matter, is the most fertile. It is called humus or humus, has a granular or lamellar structure. Humus represents plant and animal residues decomposed by microorganisms, destroying starch, cellulose, protein compounds. Its thickness is 10¸15 cm.

Above the humus horizon is plant litter layerwhich is called bedding... It consists of not yet decomposed plant debris. Below the humus horizon there is an infertile whitish layer 10¸12 cm thick. Nutrients are washed out of it with water or acids, therefore it is called washout horizon... Further, the parent rock occurs.

Over 50% of the mineral composition of the soil is formed by silica, up to 25% is accounted for by alumina, up to 10% by iron oxide and from 0.1 to 5% by oxides of magnesium, potassium, phosphorus, calcium.

The most important chemical properties of the soil, which turn it into a unique reactor, are the concentration of salts in the soil solution, acidity, which has a decisive effect on the activity of microorganisms and the absorption of nitrogen by plants, as well as the exchange or absorption capacity of the soil.

The water content of soil depends on a number of factors, including temperature and rainfall. The higher the concentration of salts in the soil solution, the less they are available to plants. Nutrients from the soil enter the plant through the root ends in ionic form.

In the processes of soil formation, living organisms, bacteria, and fungi inhabiting the soil play an important role.

Man practically does not affect the lithosphere, although the upper horizons of the earth's crust change greatly as a result of the exploitation of mineral deposits. The greatest transformation is undergone by the uppermost, surface horizon within the land, which occupies 29.2% of the earth's surface and includes lands of various categories, of which fertile soil is of the utmost importance.

Various physical, chemical and biological processes take place in the soil, which, as a result of the ingress of pollutants, are disrupted. Soil pollution is associated with pollution of the hydrosphere and atmosphere.

The main sources of soil pollution are:

- residential buildings and household enterprises... The pollutants are dominated by household waste, food waste, sewage, waste from heating systems, hospitals, canteens, hotels, shops, etc.

- industrial enterprises... In gaseous, liquid and solid industrial wastes, there are certain substances that significantly change the chemical composition of soils, contaminating them.

- heat power engineering. In addition to the formation of slags during the combustion of coal, thermal power is associated with the release of unburned particles into the atmosphere in soot, sulfur oxides and other substances that enter the soil.

- Agriculture... Fertilizers and pesticides used to protect plants from pests, diseases and to control weeds.

- transport... During the operation of internal combustion engines, nitrogen oxides, lead, hydrocarbons and other substances that settle on the soil surface or are absorbed by plants are intensively emitted.

Date added: 2014-12-15 views: 67 | Copyright infringement


Watch the video: SOIL PROPERTIES