Chemical reclamation (reclamation is a radical improvement of soils) has to be resorted to in cases where it is necessary to quickly change their properties unfavorable for plants and increase fertility. To do this, chemicals are added to the soil to improve its changing properties. IN agriculture liming is most often used acidic soils and gypsuming, and sometimes acidifying alkaline.

Liming of acidic soils

In the post-Soviet space, about half of all cultivable land is located in the non-chernozem zone. There is enough precipitation here, and at times too much. But the yields on podzolic and soddy-podzolic soils that predominate in this zone are small. The reason for their low fertility is lack nutrients, bad and sour reaction of many of them. caused by organic and partly mineral and hydrogen ions located on the surface of the smallest, colloidal soil particles.

Most crops do not grow well in highly acidic soils and produce low yields. Beetroot is especially sensitive to soil acidity. Somewhat less, but also sensitive to increased acidity, are wheat, cauliflower, and cucumbers; from fruit - , ; from herbs - a fire, . Oats and rye are weakly sensitive to acid reaction, but also react positively to liming.

There are crops that easily tolerate high acidity and do not usually require soil liming. Some of them increase productivity with incomplete liming, when strong acidity is replaced by weak acidity. These are turnips and radishes.

Liming takes one of the first places in increasing the fertility of acidic soils. It eliminates acidity, converts some toxic compounds, such as aluminum, into an insoluble and therefore harmless form for plants and, conversely, promotes the solubility of some other substances, including phosphates (by binding mobile aluminum and), and thereby increases their availability to plants. At the same time, the living conditions of beneficial microorganisms improve and their number increases. Humic substances accumulate in the soil, improving its structure. it becomes more water-breathable and easier to process.

Depending on the degree of acidity of the soil, the amount of humus and clay particles in it, it is necessary to add different amounts of lime to the soil. For example, on clay soils it is necessary to add approximately one and a half times more lime than on light loamy and sandy loam soils. Slightly acidic soils do not need liming.

In limed soils it is necessary to add minerals and... Only under this condition can you get the most out of eliminating soil acidity. top scores allows the application of lime along with organic and mineral fertilizers. Lime increases the efficiency of mineral and organic fertilizers by 25-50%. For example, the barley harvest and perennial herbs when applying 20 tons of manure and 6 tons of lime per hectare, it is equal to the yield that occurs when applying 40 tons of manure. Even applying half doses of lime significantly increases the yield. On calcareous soils winter wheat increases on average by 3-6 centners per hectare, spring wheat, barley and rye - by 2-5 centners, clover for hay - by 10-15 centners, fodder root crops - by 60 centners.

The more acidic the soil, the greater the yield increase provided by the application of lime. But one liming is very

poor soils may not give a positive result, since lime reduces the solubility of some other substances, such as potassium and trace elements. Therefore, on poor soils it is often necessary to add microelements during liming:, on some soils, sulfur,. improve not only plants, but also them against various diseases.

Remove waste from the salt lick during the production of soda. Calcium chloride is more chemically active than gypsum, but it is bad because the chlorine ion associated with it is toxic to plants. After reclamation with calcium chloride, soils need more accelerated leaching, which is only possible with artificial irrigation. After leaching they become good, fertile soils.

Solonetzes, which contain calcium carbonate starting from the very top layer, can be improved by introducing acidic industrial waste into the soil, preferably waste from the production of technical sulfuric acid. This technique is called acidification of solonetzes.

scattered over the surface of the soil and then plowed.

Acidification is also used on soils saline with soda. This most toxic salt found in soils cannot be removed by leaching. You have to first destroy the soda - combine the sodium ion with the sulfate ion - and then rinse the soil.

Chemical reclamation- an important part of the enormous work to radically improve the land that has unfolded throughout the vast territory of our country.

In the south, salinity and alkalinity of soils are carried out and eliminated; in the north, waterlogged lands are drained and harmful soil acidity is dealt with.

In accordance with Article 5 of the Federal Law of January 10, 1996 N 4-FZ “On Land Reclamation” (as amended on January 10, 2003), adopted by the State Duma on December 8, 1995 “Types and Types of Land Reclamation” depending on the nature of reclamation activities, the following types of land reclamation are distinguished: hydro-reclamation; agroforestry; cultural and technical reclamation; chemical reclamation. As part of certain types of land reclamation, the same Federal Law establishes types of land reclamation.

1. Chemical land reclamation

In accordance with Article 9 of the Federal Law, chemical land reclamation consists of carrying out a set of reclamation measures to improve the chemical and physical properties of soils. During chemical reclamation, harmful substances for agriculture are removed from the root layer of the soil. salt plants, in acidic soils the content of hydrogen and aluminum decreases, and in solonetzes - sodium, the presence of which in the soil absorption complex worsens the chemical, physicochemical and biological properties soil and reduces soil fertility.

Methods of chemical reclamation: 1) soil liming(mainly in the non-chernozem zone) - application of lime fertilizers to replace hydrogen and aluminum ions in the soil absorption complex with calcium ions, which eliminates soil acidity; 2) soil gypsum(solonetz and solonetz soils) - adding gypsum, the calcium of which replaces sodium in the soil, to reduce alkalinity; 3) acidification of soils (with an alkaline and neutral reaction) - acidification of soils intended for growing certain plants (for example, tea) by adding sulfur, sodium disulfate, etc. Chemical reclamation also includes the introduction of organic and mineral fertilizers in large doses, leading to radical improvement of the nutritional regime of reclaimed soils, for example sandy ones.

1.1 Soil liming

Tiny soil particles charged with hydrogen ions H+ act as a weak acid, causing an acidic soil reaction and low pH. On the contrary, soil particles that retain calcium, magnesium, potassium and sodium cause an alkaline reaction, high pH. Soils become acidic due to the displacement of calcium, magnesium, sodium and potassium cations by hydrogen ions H+. This process is reversible; soil pH can be increased by adding the listed elements, while the most economical is the use of calcium. Calcium is also a very important element of plant nutrition, improves the structure of the soil, makes it crumbly and granular, and stimulates the development of beneficial soil microorganisms, especially bacteria that enrich the soil with nitrogen. Magnesium also has similar properties; these elements are often used together. The addition of calcium-magnesium compounds leads to a significant improvement in plant growth.

The addition of calcium or calcium-magnesium compounds to reduce acidity is called liming. Although the term "lime" refers to CaO (quicklime), other compounds of calcium or calcium and magnesium are also called lime. Liming is carried out to bring the pH of the soil to slightly acidic (pH 6.5). If, on the contrary, you need to increase the acidity of the soil, then some nitrogen fertilizers, such as ammonium sulfate, will help, but elemental sulfur is most effective.

In our country, soils with high acidity (pH below 5.5) occupy large areas- more than 60 million hectares, including about 50 million hectares of arable land. Most of the acidic soils are located in the zone of soddy-podzolic soils. In addition, red soils, gray forest soils, many peat-bog soils and partially leached chernozems are characterized by an acidic reaction. Liming - the most important condition intensification of agricultural production on acidic soils, increasing their fertility and efficiency mineral fertilizers.

The attitude of various plants to soil reaction and liming.

For each plant species, there is a certain environmental reaction value that is most favorable for its growth and development. Most agricultural crops and beneficial soil microorganisms develop better with a reaction close to neutral (pH 6-7).

In relation to the reaction of the environment and responsiveness to liming, agricultural crops can be divided into the following groups.

1. Alfalfa, sainfoin, sugar beet, table and fodder beet, hemp, cabbage do not tolerate acid reaction - for them the optimum pH lies in a narrow range from 7 to 7.5. They respond strongly to the application of lime even on slightly acidic soils.

2. Wheat, barley, corn, sunflower, all legumes, with the exception of lupins and seradella, cucumbers, onions, and lettuce are sensitive to high acidity. They grow better with a slightly acidic or neutral reaction (pH 6-7) and respond well to liming of not only strongly but also moderately acidic soils.

3. Rye, oats, millet, buckwheat, timothy, radishes, carrots, and tomatoes are less sensitive to high acidity. They can grow satisfactorily in a wide pH range with acidic and slightly alkaline reactions (from pH 4.5 to 7.5), but a slightly acidic reaction (pH 5.5-6) ​​is most favorable for their growth. These crops respond positively to liming of strongly and moderately acidic soils in full doses, which is explained not only by a decrease in acidity, but also by increased mobilization of nutrients and improved plant nutrition with nitrogen and ash elements.

4. Flax and potatoes need liming only on medium and strongly acidic soils. Potatoes are little sensitive to acidity, and for flax a slightly acidic reaction (pH 5.5-6.5) is better. High rates of CaCO 3 , especially with limited rates of fertilizers, have a negative effect on the quality of the harvest of these crops: potatoes are severely affected by scab, the starch content in tubers decreases, and flax suffers from bacteriosis, and the quality of the fiber deteriorates. The negative effect of liming is explained not so much by neutralization of acidity, but by a decrease in assimilable boron compounds in the soil and an excessive concentration of calcium ions in the solution, which makes it difficult for other cations to enter the plant, in particular magnesium and potassium.

In crop rotations with a large specific gravity of potatoes and flax, when using high rates of fertilizers, especially potash, liming can be carried out at full rates, while it is better to apply lime fertilizers containing magnesium, shale ash or metallurgical slag, and when using CaCO 3, simultaneously apply boron fertilizers. In this case, there is no negative effect of liming on flax and potatoes, and at the same time, the yield of clover, winter wheat and other acid-sensitive crops increases.

5. Lupine, seradella and tea bush tolerate acid reaction well and are sensitive to excess water-soluble calcium in the soil, so when liming with increased doses they reduce the yield. When cultivating lupine and seradella as green fertilizer, it is recommended to apply lime not before sowing, but when plowing these crops into the soil.

Thus, for most agricultural crops increased acidity soil has a negative effect and they respond positively to liming. With increased acidity of the soil solution, the growth and branching of roots, the permeability of root cells deteriorate, and therefore the use of water and soil nutrients by plants and applied fertilizers deteriorates. With an acidic reaction, the metabolism in plants is disrupted, protein synthesis is weakened, and the processes of converting simple carbohydrates (monosaccharides) into other more complex organic compounds are suppressed. Plants are especially sensitive to increased soil acidity during the first period of growth, immediately after germination.

In addition to the direct negative effect, increased soil acidity has a multifaceted indirect effect on the plant.

The negative effect of high acidity is significant

The influence of lime on the properties and nutritional regime of soil

When adding lime, free organic and mineral acids in the soil solution, as well as hydrogen ions in the soil absorption complex, are neutralized. By eliminating acidity, liming has a multifaceted positive effect on the properties of the soil and its fertility.

The replacement of absorbed hydrogen with calcium is accompanied by coagulation of soil colloids, as a result of which their destruction and leaching are reduced and the physical properties of the soil are improved - structure, water permeability, aeration.

When lime is added, the content of mobile aluminum and manganese compounds in the soil decreases, they become inactive, therefore their harmful effect on plants is eliminated.

As a result of reducing acidity and improving the physical properties of the soil under the influence of liming, the vital activity of microorganisms and their mobilization of nitrogen, phosphorus and other nutrients from soil organic matter are enhanced. In limed soils, the processes of ammonification and nitrification occur more intensively, nitrogen-fixing bacteria (nodule and free-living) develop better, enriching the soil with nitrogen at the expense of air nitrogen, resulting in improved nitrogen nutrition of plants.

Liming helps convert aluminum and iron phosphates, which are difficult for plants to access, into more accessible calcium and magnesium phosphates. Liming affects the mobility in the soil and the availability of microelements for plants. Improved plant nutrition with nitrogen and ash elements is also due to the fact that on limed soils plants develop more powerful root system, capable of absorbing more nutrients from the soil.

Determining the need for soil liming and the rate of lime

The effectiveness of liming depends on the acidity of the soil: the higher the acidity, the greater the need for liming and the greater the increase in yield. Therefore, before applying lime to a particular field, it is necessary to determine the degree of acidity of the soil and its need for liming, and establish the rate of lime in accordance with the characteristics of the soil and the cultivated plants.

The need for liming the soil can be approximately determined by some external signs. Acidic strongly podzolic soils usually have a whitish tint and a pronounced podzolic horizon, reaching 10 cm or more. Increased acidity of the soil and its need for liming are also indicated by poor growth and severe loss of clover, alfalfa, and winter wheat during overwintering, and the abundant development of acidity-resistant weeds: sorrel, pickleweed, field torica, creeping buttercup, whiteweed, and pike.

The soil's need for liming can be determined with sufficient accuracy for practical purposes by the exchangeable acidity (pH of the salt extract). When the pH value of the salt extract is 4.5 and below, the need for liming is strong, 4.6-5 is medium, 5.1-5.5 is weak, and at a pH greater than 5.5 there is no need. Lime rates also depend on the mechanical composition of the soil and the characteristics of the cultivated crops.

The amount of lime required to reduce the increased acidity of the arable soil layer to a slightly acidic reaction (to a pH value of the salt extract of 5.6-5.8), favorable for most crops and beneficial microorganisms, is called the full norm.

To better organize liming, zonal agrochemical laboratories, based on an agrochemical survey of soils, compile and transmit to farms cartograms of soil acidity, which highlight areas with varying degrees of acidity and the need for liming.

Use the following materials for liming:

Quicklime - CaO. Should be extinguished before use, i.e. moisten with water until crumbly. As a result of the reaction, slaked lime is formed - fluff. Contains only calcium, no magnesium.

Slaked lime (fluff) - Ca(OH)2. The result of the reaction of quicklime with water. Reacts very quickly with soil, approximately 100 times faster than limestone (calcium carbonate). When using fluff, its amount is reduced by 25%. Contains only calcium, no magnesium.

Ground limestone (flour) - CaCO3, in addition to calcium, contains up to 10% magnesium carbonate MgCO3. The finer the limestone grind, the better. One of the most suitable materials for soil deoxidation.

Dolomitic limestone (flour) contains up to 50% dolomite (CaCO3 * MgCO3), at least 13-23% magnesium carbonate. One of the best materials for liming the soil.

chalk (crushed form),

marl is a silty material primarily composed of calcium carbonate. If there is an admixture of earth, then the application rate should be increased.

open hearth slag (crushed form),

shell rock (crushed).

Wood ash is a complex fertilizer; in addition to calcium, it contains potassium, phosphorus and other elements. You cannot use ash from newspapers, because... it may contain harmful substances.

It can be recommended to use, first of all, crushed limestone, especially dolomite - dolomite flour containing both calcium and magnesium. This not only neutralizes the acidity of the soil, but also supplies important plant nutrients. The addition of these elements to the soil improves its structure and stimulates the development of beneficial soil microorganisms, especially bacteria that enrich the soil with available nitrogen.

Slaked lime is an alkali, so it is easy to re-lime the soil with it. Dolomite, ground limestone, chalk are carbonates that dissolve carbonic acid in the soil, so they do not burn the plants; their effect is much milder. The best material for liming is dolomite flour, which contains calcium and magnesium at the same time.

Gypsum (calcium sulfate) and calcium chloride are not suitable for soil deoxidation. These compounds do not deoxidize the soil, although they contain calcium.

Gypsum (calcium sulfate - CaSO4) contains sulfur in addition to calcium and therefore does not alkalize the soil. Gypsum is used as a calcium fertilizer on saline (and therefore alkaline) soils that have an excess of sodium and a lack of calcium.

Calcium chloride (CaCl2) contains chlorine in addition to calcium, and therefore also does not alkalize the soil.

SOIL MELIORATION is a set of measures aimed at improving soil properties and soil formation conditions by direct impact on soils or indirectly through soil formation factors. When soil reclamation, limiting factors and corresponding reclamation techniques are taken into account.

Limiting factors and basic reclamation methods for their elimination

III. Chemical reclamation Justification of the need for carrying out. Methods and types of chemical reclamation. Differentiation of application of doses of mineral fertilizers depending on physical and geographical conditions. Liming, gypsum, acidification, peat, use of sapropel. The problem of using pesticides. On taking into account V.I. Vernadsky’s law on the physical and chemical unity of living matter when using chemical plant protection products.

IV. Phytomelioration Meaning and conditions. Basic methods of creating forest plantations. Structures of forest strips. Phytomelioration of sandy spaces. The influence of phytomelioration on natural conditions. Efficiency of phytomelioration.

VI. Snow reclamation The importance of snow reclamation. Zoning of the territory of the CIS according to the need for snow reclamation, their types and methods of implementation. The influence of snow reclamation on natural conditions.

VII. Climate reclamation The meaning and prerequisites of climatic reclamation. Macro-, meso- and microclimatic reclamation. Methods and techniques for climate reclamation: agrotechnical, hydraulic, phytomeliorative and engineering. The problem of active influences on macro- and mesoclimatic processes. Hailstorm. Unintentional climate change. The problem of the “greenhouse effect”. Efficiency of climate reclamation.

Federal Law of January 10, 1996 No. 4-FZ “On Land Reclamation” (as amended on January 10, 2003) Adopted State Duma December 8, 1995

Chapter II. Types and types of land reclamation

Article 5. Types and types of land reclamation Depending on the nature of reclamation measures, the following types of land reclamation are distinguished: hydro-reclamation; agroforestry; cultural and technical reclamation; chemical reclamation. This Federal Law establishes types of land reclamation as part of certain types of land reclamation.

Article 8. Cultural and technical land reclamation Cultural and technical land reclamation consists of carrying out a set of reclamation measures to radically improve the land. This type of land reclamation is divided into the following types of land reclamation: clearing of reclaimed lands from woody and herbaceous vegetation, hummocks, stumps and moss; clearing reclaimed lands of stones and other objects; reclamation treatment of solonetzes; loosening, sanding, claying, earthing, planting and primary tillage; carrying out other cultural and technical works.

Article 9. Chemical land reclamation Chemical land reclamation consists of carrying out a set of reclamation measures to improve the chemical and physical properties of soils. Chemical land reclamation includes soil liming, soil phosphorite treatment and soil gypsum.

Chemical reclamation,

a system of measures of chemical influence on the soil to improve its properties and increase agricultural productivity. crops When chemical planting is used, harmful substances for agriculture are removed from the root layer of the soil. salt plants, in acidic soils the content of hydrogen and aluminum decreases, in solonetzes - sodium, the presence of which in the soil absorption complex worsens the chemical, physicochemical and biological properties of the soil and reduces soil fertility.

Methods of painting: soil liming(mainly in the non-chernozem zone) - application of lime fertilizers to replace hydrogen and aluminum ions in the soil absorption complex with calcium ions, which eliminates soil acidity; soil gypsum(solonetz and solonetz soils) - adding gypsum, the calcium of which replaces sodium in the soil, to reduce alkalinity; soil acidification (with an alkaline and neutral reaction) - acidification of soils intended for growing certain plants (for example, tea) by adding sulfur, sodium disulfate, etc. Chemical methods also include the application of organic and mineral fertilizers in large doses, leading to radical improvement of the nutritional regime of reclaimed soils, for example sandy ones.

Certain techniques of painting were known in ancient times. In the 16th-18th centuries. liming was used in Great Britain, Germany, Holland and other European countries.

The first studies of the effectiveness of lime application were carried out in Russia by D.I. Mendeleev in 1867-69. In subsequent years, issues of liming were studied by A. N. Engelhardt, P. A. Kostychev, P. S. Kossovich, D. N. Pryanishnikov. The scientific foundations of chemical painting were laid by K. K. Gedroits, who developed the theory soil absorption capacity.

There are hydraulic, agrotechnical, biological, chemical,

cultural and technical, climatic, thermal, water management

reclamation.

Hydraulic reclamation involves the regulation of water and

air regimes of soils with excessive moisture (drainage), with

insufficient water content in the root layer of soil (irrigation), and

also during soil washout and erosion (anti-erosion measures).

Agrotechnical reclamation (agromelioration) - agrotechnical techniques

regulation of water and air modes soil and surface runoff.

In relation to objects of excessive moisture for agromelioration

include deep loosening of soils, deep plowing, creation of powerful

cultivated arable horizon (measures to increase

accumulating capacity of soils), mole (increases soil aeration), and

also selective furrowing, narrow paddock plowing along a slope,

surface profiling, combing, or the installation of small temporary

drainage network, etc.

Biological reclamation is necessary to increase soil fertility,

preventing water and wind erosion using grass and wood

vegetation. The activities include: forest reclamation - improvement

unfavorable climatic, soil and hydrological conditions with

assistance in planting forests; sowing crops of ameliorants (holophytes -

plants that live on saline lands have the ability to

soil salinity); biological drainage.

Chemical reclamation improves the chemical properties of the soil (liming

acidic soils, gypsuming of solonchaks and solonetzes, fertilizers, etc.).

Cultural and technical reclamation improves the surface and configuration

fields, primary development. The activities include cutting tussocks,

uprooting of stumps and bushes, soil milling, primary application

Climate reclamation is necessary to improve climate conditions

fields and crops. The measures include fine sprinkling.

Thermal reclamation to improve the thermal regime of soils, water and

ground layer of air. The activities include mulching,

snow retention, irrigation with thermal waters.

Water reclamation is necessary to improve the condition of water

facilities and water quality. Activities include clearing water bodies,

creation of water protection zones, fight against overgrowth and siltation of water bodies,

creation of recreation areas.

PHYTOMELIORATION(from ... fit , phyto ... And land reclamation ), a set of measures to improve the conditions of the natural environment by cultivating or maintaining natural plant communities (creating forest belts, curtain plantings, sowing herbs). Yu. P. Byalovich (1970) distinguishes F. bioproduction(increasing the quantity and quality of products useful to humans), humanitarian(improving the environment to optimize the physical and spiritual state of a person), engineering(improving the operating conditions of engineering structures), environmental(preservation and improvement of biocenoses, the natural environment as a whole), interior(improving the indoor environment

Sanding the soil Soil sanding is a method of reclamation of heavy clay soils with unfavorable water and physical properties. properties by adding sand to them. Increases the water permeability of soils and the reserves of useful moisture in them; makes them easier to process. Information taken from the site geoman.ru

Soil claying Soil claying - a method of reclamation sandy soils by adding clay to them in order to improve their water and physical properties. properties. It is usually used on sandy soils, mainly 30 kg E. t. 1. in irrigated oases to increase irrigation efficiency and reduce irrigation and water costs. Information taken from the site geoman.ru

In order to bring the soil reaction to the range from slightly acidic to slightly alkaline, which is necessary for almost all plants, chemical agents are used. soil reclamation. Acidic soils are periodically limed, and alkaline soils, especially solonetzes, are gypsumed.
Most crops and soil microorganisms develop better in slightly acidic or neutral soil. At the same time, some plants cannot withstand acidic soils, others grow and develop well. Thanks to soil reclamation we determine what effect soil acidity can have on plants, and the effect can be both direct and indirect negative. Direct action slows down the growth of the root system, its permeability to nutrients, shifts the correct ratio in the plant’s absorption of cations and anions, and disrupts metabolism.
The indirect effect is expressed in a sharp decrease in soil fertility and the harmful effect of hydrogen ions on the mineral part of the soil. It becomes depleted of colloids, which are washed away to a depth inaccessible to plants. The lack of absorbed calcium and magnesium in the soil causes a sharp deterioration in physical and physical and chemical properties soil. Free aluminum and manganese ions appear in the soil solution, which are toxic to plants, and the amount of molybdenum in the soil also decreases. Soil acidity inhibits soil organisms and, above all, nitrophicators and nitrogen-fixing bacteria, soil fauna. The main reason for the shift in soil reaction is the removal of calcium and magnesium with the crop and their leaching from the soil.

Soil liming

To neutralize acidity, carry out liming of acidic soils. All lime fertilizers can be divided into two groups: natural carbonate rocks, which are both hard and loose, and industrial waste rich in lime.
The main natural lime material is ground limestone, which contains up to 95% calcium and magnesium carbonates. Limestones require grinding to be added to the soil. The finer the grind, the better flour mixes with the soil, acts faster and reduces acidity more strongly. When natural limestones are fired, burnt lime is obtained, which transforms when interacting with water into slaked lime.
Slaked lime is a fast-acting calcareous microfertilizer, especially valuable for clay soils. This is due to its relatively good solubility in water. The effectiveness of slaked lime is much higher than ground limestone. Great importance loose calcareous rocks are used for liming. They do not require grinding, are no less effective than ground limestone, and are much cheaper due to the fact that they can be mined using economic methods. These include: tuff, marl, peat tuff, natural dolomite flour. Calcareous tuffs contain from 70 to 98% calcium carbonate. They are found in river valleys, in places where springs emerge, hence the second name – spring lime.
By appearance calcareous tuffs are loose granular rock, gray, sometimes with rust-colored spots. Before application, tuffs are sifted through screens to remove large particles.
Marl is a calcareous material in which calcium carbonate is mixed with clay and sand, containing calcium carbonate from 25 to 50%. It is found both loose and in a dense state, but if left for the winter, under the influence of rain and snow it turns into a loose state.
Peat tuffs are low-lying peats in which the presence of lime is 10-70%. It is used on soils where there is very little humus, mainly on podzolic soils.
Natural dolomite flour is a rock with a high content of calcium and magnesium carbonates. The most valuable lime fertilizer for liming acidic sandy soils, which often suffer from a lack of magnesium.
Estimated requirement soil liming The white color of the arable layer, as well as the growth of indicator plants on the site: sorrel, horsetail, tricolor violet, can serve as a reason. The accuracy of the need for liming is determined by agrochemical analysis based on the pH of the salt extract, after which a cartogram is drawn up. Strongly acidic soils are limed first. Medium and slightly acidic limes are limed selectively, taking into account the crops that will be grown on the site. Neutral or similar soils do not need liming. When determining the degree of soil need for liming, it should be taken into account mechanical composition and a set of crops in crop rotation. The dose of lime is most often calculated by hydrolytic acidity.
It is best to apply lime in dry, windless weather. Calculated doses of lime are applied immediately or in several doses. This is due to the fact that some crops react negatively to a sharp change in pH. Full doses of lime are applied during autumn plowing. Small doses are applied for cultivation or harrowing.
Burnt or slaked lime cannot be applied together with organic fertilizers: manure, slurry or ammonia mineral fertilizers, as this will lead to their loss of nitrogen. Liming of acidic soils with low potential fertility should be accompanied by the application of organic and mineral fertilizers, since liming alone does not solve the problem of soil cultivation.

Plastering

Solonetzes and highly saline soils contain sodium cations, which, when absorbed, cause poor physical properties soils, especially physical and mechanical: stickiness, cohesion, resistance to tillage. The alkaline reaction of solonetzic and solonetz soils is detrimental to plants. Cultivation and increase in fertility of solonetzes is carried out by gypsum. When gypsum is added to the soil, calcium ion displaces sodium ion, the soil goes into a structural state, and the physical and biological properties of the soil improve. Simultaneously with gypsuming, the soil is washed with water to remove sodium sulfate from the arable layer, which is formed when gypsum is added. The simultaneous use of irrigation, the application of manure and mineral fertilizers dramatically increases the effect of gypsum.
The dose of gypsum depends on the degree of salinity of the soil and is 3-10 tons per 1 ha, but usually the dose is calculated by agrochemical analysis. Action plastering usually appears at 8-10 years of age.

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23.10.2017

When growing most cultivated plants, it is necessary to take into account many various factors: weather and climatic conditions, soil fertility, humidity, soil composition, level groundwater And so on.

High alkalinity, like high soil acidity, can also create very unfavourable conditions for the growth and development of most crops, since they have a direct impact on the degree of penetration of heavy metals into the internal tissues of plants.

To determine the acidity of the soil, the pH indicator is used ( acid-base balance), the values ​​of which usually range from three and a half to eight and a half units. If the “pH” of the soil is neutral (within six or seven units), then heavy metals remain bound in the soil and only a tiny amount of these harmful substances enters the plants.

How to determine soil acidity and improve its “pH” can be read .

Alkaline soil has low fertility because the soil is usually heavy, viscous, poorly permeable to moisture and poorly saturated with humus. Such soil is characterized by a high content of calcium salts (lime) and elevated pH values.

According to their characteristics, alkaline soils can be divided into three main types:

· Weakly alkaline soils (pH value of about seven or eight units)

· Moderately alkaline (pH value about eight, eight and a half units)

· Strongly alkaline (pH value above eight and a half units)

Alkaline soils are very different - these are solonetz and solonetzic soils, lands that contain most of stony loam, as well as heavy clay soils. In any case, they are all calcareous (that is, saturated with alkali).

To determine the presence of lime in the soil, just pour a little vinegar onto a lump of soil. If lime is present in the soil, instantaneous chemical reaction, the earth will begin to hiss and foam.

The easiest way to determine exact value"pH" using litmus paper (specially provided for this purpose standard indicator, showing the acidity of the soil). To do this, you should prepare not a large number of aqueous solution in the form of a liquid suspension (at the rate of one part earth to five parts water), and then dip a litmus indicator into the solution and see what color the paper turns.

Some plants can also indicate the presence of alkaline soil, for example, chicory, bellflower, thyme, spurge, and woodlice.

Calcareous soils are most often located in the southern part of the steppe and forest-steppe zones of Ukraine and are alkaline chestnut and brown soils with poor vegetation. These soils are characterized by a low humus content (no more than three percent) and low humidity, so in order to successfully grow on these lands cultivated plants, it is necessary to oxidize the soil and provide additional irrigation.

As for solonetzes and solonchaks, these are extremely problematic, infertile lands, which also have a high salt content. These soils are characteristic of the southern steppes, present on the sea coasts and in the coastal areas of large and small rivers in our country.

Ways to Improve Alkaline Soil

Improve pH alkaline soils This is possible through reclamation measures and the addition of calcium sulfate, which is popularly called gypsum, into the soil. When regular gypsum is added, calcium displaces the absorbed sodium, as a result of which the structure of the solonetz horizon improves, the soil begins to pass moisture better, as a result of which excess salts are gradually washed out of the soil.

The effect of adding gypsum is not limited only to increasing the amount of sulfur in the soil, since it first of all improves the structure and quality of the soil, helping to increase the content of bound sodium in it.

Granular sulfur is also used as an excellent soil oxidizer, which should be applied gradually (about twenty kilograms per hectare of area), with an interval of three or more months. But it should be remembered that the result from adding sulfur can be expected only after a year or even after several years.

To improve alkaline soil, it is recommended to perform deep plowing, but without ameliorating additives it is usually less effective.

To neutralize alkalinity caused by the presence of sodium carbonates and bicarbonates in the soil, weak solutions of various acids, most often sulfuric, should be used. A similar effect is exerted by acidic salts, which form acids due to the hydrolysis reaction (for example, iron sulfate is often used as a component for the reclamation of alkaline soils).

In practice, to improve soil alkalinity, farmers sometimes use waste from the phosphorus mining industry, that is, phosphogypsum, which in addition to calcium sulfate contains impurities of sulfuric acid and fluorine. But recently, scientists have sounded the alarm, since phosphogypsum, although it neutralizes increased alkali, also pollutes the soil with fluorine. Plants can react differently to a given substance (for example, it has been proven that increased content fluoride in plants intended for animal feed can be quite toxic).

In slightly alkaline soils, the structure of the fertile horizon is improved by plowing with the introduction of increased doses of organic fertilizers, which acidify the soil. The best of them is rotted manure, to which you should add ordinary superphosphate (about twenty kilograms per ton of manure) or phosphorus flour (about fifty kilograms per ton of humus). To reduce soil alkalinity, you can also add peat moss or bog peat to the soil. Pine needles acidify the soil well pine trees, which is often used as a basis for soil mulching. Compost made from rotted oak leaves gives a good result for normalizing alkalinity.

In arid areas with little monthly rainfall, additional irrigation is required.

Alkaline soil is significantly improved by planting green manure plants, which are an excellent source of biological nitrogen. As green manure crops, such crops as lupine (contains a large amount of protein substances) and other plants of the legume family, as well as seradella, clover, sweet clover, white mustard, rye and buckwheat.

When using mineral fertilizers, you should choose those that acidify the soil, but do not contain chlorine (for example, ammonium sulfate).