The increased content of acids in the soil reduces crop yields. Optimum acidity is achieved with liming. The most effective chemical reclamation is carried out in the fall. The application rate for limestone material can be calculated independently. When and how to lime the soil, you can find out by watching the video.

Liming technology, substances used for liming

To a large extent, the yield and quality of crops depends on the acidity of the soil. The increased acid content in the soil prevents plants from fully assimilating microelements. Such essential substances as potassium, magnesium, phosphorus, calcium do not go to plants, even if fertilizers are applied. Plants grow poorly, do not bear fruit. The acid level can be lowered by adding acid neutralizing substances. These substances include:

• slaked lime;
• dolomite flour;
• wood ash;
• peat boots;
• waste of sugar production;
• blast furnace slag.

Attention! You cannot lime the soil with gypsum, it crystallizes salts in the soils, which leads to an increase in acidity.

You can determine the increased acid content in the soil folk methods... If horsetail, sorrel, plantain, heather, mint grow well on the site, then the soil is acidic. A more accurate scientific method for determining acidity can be performed in the laboratory. An easier way to determine the acid content in points is possible using an indicator that is sold in flower shops. To do this, wrap a handful of soil in a cloth, immerse it in water for a couple of minutes. We lower the indicator into the cloudy water. Compare the color change of the indicator with the color of the scale:

• 3-4 - very sour;
• 4-5 - sour;

Checking the acidity of the soil

• 5-6 - slightly acidic;
• 7 - neutral;
• 8-9 - alkaline.

The acidity and composition of the soil are interdependent. The greatest amount of acid is found in clay, sandy soils are considered less acidic.

Optimal acidity, types of liming

Each plant reacts differently to acid content:

1. Cabbage, as well as beets, do not grow well on soils with high acidity.
2. Tea and lupine grow well on acidic soils.
3. Legumes, as well as corn, lettuce, onions and cucumbers, prefer neutral soil.

Liming the soil can lead to an improvement or deterioration in its quality. First, you need to determine which crops will be grown on the site. It is possible to carry out partial liming of individual beds intended for certain crops.

Examples of optimal acidity for horticultural crops:

• raspberry and gooseberry bushes - 5.5;
• different types of currants - 6;
• pear and apple tree - 6.5;
• plum -7.

Different crops prefer different soil acidity

Liming is basic and supportive. The main gardeners spend 1 time. Maintenance liming procedure - every 4-5 years. For soil deoxidation, choose the autumn or spring period. Chemical reclamation in autumn is most effective. We evenly distribute the required amount of lime material over the surface of the soil. At the same time, we apply fertilizers with a high content of magnesium and potassium.

Advice. The soil must be dug to a depth of 15-20 cm. The application of lime material to the surface without loosening reduces the effectiveness of liming.

Spring deoxidation is carried out before making chemical fertilizers... Lime material is spread over the surface, then fertilizers are applied and the soil is dug to a depth of 4-6 cm.

Dosing of liming agents depending on the acid content of the soil

When liming the soil, it is important to comply with the norms, since different lime materials have different percentages.

When adding fluff (slaked lime), the rates are distributed as follows:

1. 500-600 g per 1 m² with high soil acidity (pH less than 4).
2. If the acid content in the soil is high (pH = 4), add 400-500 g per 1 m².
3. If the acidity index varies from 4 to 5, add 300-400 g per 1 m².
4. In slightly acidic soils (pH = 5-6) add 200-300 g per 1 m².

Soil liming is carried out in the fall

These values ​​are only suitable for slaked lime. Chalk, cement dust and other substances are introduced in different proportions, since their calcium content is different:

• slaked lime - 130%;
• chalk -100%;
• dolomite flour - 90-95%;
• crushed chalk - 90%;
• lake lime -80%;
• cement dust 75%;
• marl - 70%;
• peat ash - 50%.

• determine the rate of slaked lime for the site;
• multiply this indicator by 100;
• then divide by the percentage of lime in the substance.

Let's calculate the amount of lake lime per 1 m². Suppose that the acidity of the soil is 4. For 1 m², 400-500 g of lime must be added. 500 x 100: 80 = 625 g of lake lime per 1 m². For marl with soil acidity equal to 5: 200 x 100: 70 = 285.7 g per 1 m².

With optimal acidity, plants develop better

Fluff can be made at home. Quicklime is scattered on a hard surface, poured over with water. As a result of a chemical reaction, lime is formed that is safe for plants.

As a last resort, you can lime the soil without determining the acidity:

• clay soils - 600-700 g of lime per 1 m²;
• loam - 500 g per 1 m²;
• sandy soils - 300-400 g per 1 m².

Adding lime has a beneficial effect on plants:

• enriches the soil with microelements, including magnesium;
• plants almost do not accumulate toxic substances;
• the soil structure becomes looser;
• favorably affects the reproduction of beneficial bacteria.

The liming of the soil can be carried out independently, the main thing is to know the acid content in the soil at the site, to calculate the required amount of different lime materials. Each plant is adapted to a certain level of acidity. Liming the area or individual beds will help to achieve a higher yield.

Soil liming is the process of introducing special additives into the soil to reduce the acidity level. For this purpose, you can use lime, chalk powder, lime tuff, marl, shale and peat ash, white and dolomite flour, as well as cement dust and open-hearth slag.

But, for example, sodium salts for liming the soil are not suitable, since it will become unsuitable for efficient cultivation of crops.

Soil liming: when and what is it used for?

The introduction of lime into the soil leads not only to the fact that the acidity of the soil decreases, but also to an increase in the proportion of calcium, magnesium and other useful micro- and macroelements. Therefore, liming the soil is not only a decrease in acidity, but also an important fertilization for plants.

The pluses of liming also include an increase in soil looseness - such a soil will absorb moisture well and keep it close to the surface. In this way, the roots of the plants will be optimally saturated with water, even in hot weather. In conditions of moisture and saturation with useful elements, soil microflora rapidly develops, which leads to natural fertilization of the beds. At the same time, the roots will not absorb a large number of toxic substances, as it would be if liming was not carried out on time.

It is impossible to lime the soil and fertilize it with manure at the same time, as the result will be an insoluble and useless mixture for plants.

Too acidic soils are bad for the development of crops. If there is soil with high acidity on the site, it will be difficult to achieve good harvest all types of beets, as well as cabbage, corn and legumes. If the soil is also sandy, then the plantings will lack magnesium and calcium. Manganese and aluminum compounds harmful to plants, on the contrary, will show increased activity.

Determination of soil acidity

At home, you can independently check whether liming of acidic soils is required on your site. The easiest way for this purpose is to use litmus tests or special devices to find the limit of soil acidity. If there is no way to conduct an accurate analysis, you will have to rely on "folk remedies":

1. Weeds such as horsetail and dandelion grow very quickly on soil with a lack of alkali. Sorrel, mint and plantain are preferred in acidic soil. Clover, coltsfoot and quinoa grow well on alkaline or neutral soil.
2. The top layer of the soil looks like wood ash; in some areas, a grayish bloom is even noticeable on the surface.
3. Pay attention to the natural puddles and lowlands in the area - after the rain, the water turns red, sometimes an inconspicuous film of rainbow colors appears at the top.
4. Take a small handful of soil from the plot and sprinkle it with vinegar. If nothing happens, this is also a sign of increased acidity (since vinegar is an acid, you should not expect a violent reaction when mixed with acidic soil). But if the ground begins to hiss and foam, then it is either neutral or alkaline, in this case liming of the soil is not necessary.

Liming and gypsum soil

Plastering differs from liming the soil with lime in that it not only lowers the acidity, but allows you to get rid of excess sodium in the soil. Sodium adversely affects physical and Chemical properties land, and the cultivation of crops in such areas becomes much more difficult.

What chemical reactions occur after gypsum is added to the soil? The percentage of sodium decreases, and it is replaced by abundant calcium introduced into the soil. Since calcium is beneficial for plants, its introduction has a positive effect on the growth of crops.

For gypsum, industrial waste with a high content of gypsum and phosphorus is usually used, as well as raw gypsum. To determine how much gypsum needs to be added, a biochemical analysis of the soil is preliminarily carried out, determining the amount of sodium it contains. On average, you will need from 3 to 15 tons of fertilizer, and the greatest need for gypsum is felt by salt licks and solonetzic soils.

Plastering can be done during plowing, sowing perennial plants or irrigation. As a result, the yield of cultivated crops increases by 3-6 centners per hectare. It should be borne in mind that the most effective gypsum plastering of irrigated areas, but the reclamation period of the site is reduced.

Types of lime fertilizers

For liming, both powders (chalk, dolomite, limestone) specially obtained by roasting or grinding can be used, as well as industrial waste with a high percentage of lime.

The main means of liming the soil is lime flour, almost entirely composed of calcium carbonate (CaCO3). If, in addition to calcium carbonate, a mixture contains a large amount of magnesium carbonate (MgCO3), then such a mixture is called dolomite flour. Magnesium breeds are more durable, and it is somewhat more difficult to get flour from them, but the result is a fertilizer that is more useful for agricultural crops. The greatest deficiency in magnesium salts is experienced by sandy soils, therefore, pure lime is practically not used for them. For achievement better result marl and even ordinary cement dust can be added to the mixture.

The quality of the powders applied to the soil is determined by the percentage of calcium and magnesium carbonates (this is especially important for industrial waste) and how fine the grinding is. Large particles are less soluble, so the soil "assimilates" them more slowly. For maximum efficiency, it is advisable to choose limestone flour with a grinding thickness of no more than 0.25 mm.

The agent for effective liming is slaked lime. It is a powder obtained by firing limestone rocks, combined with water. Slaked lime or fluff in the first few years neutralizes the soil faster than conventional lime flour. After several courses of liming, the effectiveness of these two compositions becomes approximately the same.

If it is not possible to carry out classical liming, at home you can use stove ash - it is poured under the root of acid-sensitive plants.

Soil liming: application rate

Usually, when calculating, they are guided by the so-called full norm - the amount of lime (tons per hectare), at which the acidity indicators decrease to a weakly acidic reaction.

Before calculating how much lime is needed for the site, it is necessary to determine not only the area occupied by the plantings, but also the following characteristics:

1. The mechanical composition of the soil.
2. Natural acidity of the soil on the site.
3. Features of crops grown in this area. For example, clover, cabbage and beets are sensitive to lime fertilization, so it is advisable to provide a full rate of lime in the areas occupied by them. But acidity has practically no effect on lupine or potatoes - there is no point in overloading the soil with lime, and therefore you can reduce the rate by one or two-thirds.

The rate of liming of the soil with any particular mixture is calculated according to the following formula: H = Rate of lime based on the acidity calculated in advance * 10000 and divided by the Percentage of lime in the mixture * (100 is the percentage of coarse particles).

Here, the lime rate is taken into account in tons per hectare. Large particles are particles with a diameter greater than 1 mm.

If it is necessary to liming acidic soil on a large scale, it is possible to preliminarily draw up a map of the site indicating the crops. In some places, the acidity may be higher, and vice versa, so for optimal placement of the beds, you need to take into account the difference between the soils.

Methods and terms of liming the soil

It is best to liming the soil in the spring before planting crops or in the autumn before digging up the beds so that the introduced substances do not remain on the surface. If spring liming is planned, then the procedure must be carried out no later than three weeks before planting.

Dolomite flour can be used for liming even in winter period- for this, it is scattered in the fields right on top of the snow cover.

Primary liming is carried out before planting table and fodder beets or cabbage. Other types of crops allow not to fertilize the soil with lime again and to alternate planting, while the effectiveness of fertilization does not decrease.

During the season, part of the introduced lime is lost, therefore, re-liming is periodically (not necessarily every year) carried out. For the first time, such an amount of lime or dolomite flour to completely neutralize the acidity of the soil. Repeat - only small doses, constantly monitoring acidity levels and maintaining optimal calcium and magnesium levels.

How to properly fertilize the soil with lime:

1. If lime or dolomite mixture is not finely ground, then before adding to the soil, it is pounded to a powder state.
2. The finished composition is evenly distributed over the entire area.
3. Lime is mixed manually or with the help of agricultural machinery at a depth of 20-25 cm.If the procedure is repeated, and an incomplete amount of lime is added, then the depth of the loosened soil should not exceed 4-6 cm.

Autumn liming allows you to more accurately adjust the ratio of acids and alkalis in the soil, and the result will last for a longer period than when lime was applied in spring. Fertilization with lime in the fall is even safer, since some formulations (for example, slaked lime or wood ash) are quite caustic and can damage plant roots by direct contact. In this case, there is no need to loosen the soil deeply - after rain and snowfall, the mixtures naturally reach the required depth.

With the correct preliminary calculation, it will be necessary to repeat the procedure no earlier than in 5-7 years.

If desired, you can mix lime or dolomite flour, as well as gypsum powder with boric, copper, cobalt, potassium or even bacterial fertilizers. Superphosphates are also suitable for greater fertility.

Results of regular liming

Liming acidic soils is a simple and environmentally friendly way to increase the fertility of the land on the site. Factors due to which a positive effect is achieved:

• activation of the vital functions of some useful for garden plants microorganisms such as nodule bacteria, etc .;
• increasing water resistance and mechanical loosening of the soil, due to which water, together with fertilizers, does not leave the roots and tubers for a long time;
• enrichment of the earth with useful elements (calcium, magnesium, fluorine);
• preventing the absorption of toxic substances by plants - this is especially important for areas adjacent to industrial zones;
• faster assimilation of mineral elements.

All of these factors make it possible to collect an ecologically clean and rich harvest with the onset of autumn.

To make sure of the need for timely liming of the soil, you can calculate the economic benefit from the procedure - the payback time and net profit... To do this, it is necessary to calculate the costs of purchasing lime mixtures and their distribution over the territory, as well as the growth of crops for the years following liming. Obviously, the fastest possible payback can be achieved if liming is carried out on strongly acidic soils and subsequently planted with crops sensitive to liming (vegetables, fodder plants and potatoes). As a result of the neutralization of the soil, the plants cease to suffer from the harmful effects of acids and receive much more nutrients than before.

Liming the soil in autumn - video

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

Attitude different plants to the reaction of the soil and liming For each species of plants there is a certain value of the reaction of the environment most favorable for its growth and development. Most crops and beneficial soil microorganisms develop better with a reaction close to neutral (pH 6-7).

With regard to environmental response and responsiveness to liming, crops can be classified into the following groups.

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

2. Wheat, barley, corn, sunflower, all legumes, with the exception of lupins and seradella, cucumbers, onions, 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 and moderately acidic soils.

3. Rye, oats, millet, buckwheat, timothy, radish, carrots, 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 the weakly acidic reaction (pH 5.5-6) ​​is most favorable for their growth. These crops respond positively to the liming of strongly and moderately acidic soils with full doses, which is explained not only by a decrease in acidity, but also by an increase in the mobilization of nutrients and an improvement in plant nutrition with nitrogen and ash elements.

4. Flax and potatoes need liming only on medium and strongly acidic soils. Potatoes are not very sensitive to acidity, and for flax, a slightly acidic reaction (pH 5.5-6.5) is better. High CaCO norms 3 , especially with limited fertilization rates, have a negative effect on the quality of the crop of these crops, potatoes are strongly affected by scab, the starch content in tubers decreases, and flax becomes ill with bacteriosis, and the quality of fiber deteriorates. The negative effect of liming is explained not so much by the neutralization of acidity as by a decrease in the assimilable boron compounds in the soil and an excessive concentration of calcium ions in the solution, which makes it difficult for the plant to enter other cations, 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 slags, and when using CaCO 3 apply boric fertilizers at the same time. In this case, there is no negative effect of "liming" on flax and potatoes, and at the same time, the yield of clover increases, winter wheat and other crops sensitive to acidity.

5. Lupines, seradella and tea bush are well tolerated and sensitive to an excess of water-soluble calcium in the soil, therefore, when liming at higher doses, they reduce the yield. When cultivating lupine and seradella for green fertilization, it is recommended to apply lime not before sowing, but when plowing these crops into the soil.

Thus, for most agricultural crops, increased soil acidity has a negative effect and they respond positively to liming. The adverse effect of the acid reaction on plants is very versatile, the direct harmful effect of an increased concentration of hydrogen ions is combined with the indirect influence of a number of factors accompanying the acid reaction. With an increased acidity of the soil solution, the growth and branching of roots, the permeability of the root cells, deteriorate, therefore, the use of water and nutrients of the soil and applied fertilizers by plants deteriorates. With an acidic reaction, the metabolism in plants is disturbed, protein synthesis is weakened, the processes of conversion of simple carbohydrates (monosaccharides) into other more complex ones are suppressed organic compounds... Plants are especially sensitive to increased soil acidity in the first period of growth, immediately after germination.

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

Acidic soils have unfavorable biological, physical and chemical properties. The colloidal part of acidic soils is poor in calcium and other bases. Due to the displacement of calcium by hydrogen ions from soil humus, its dispersion and mobility increase, and the saturation of mineral colloidal particles with hydrogen leads to their gradual destruction. This explains the low content of colloidal fraction in acidic soils; therefore, they have unfavorable physical and physicochemical properties, poor structure, low absorption capacity and poor buffering capacity.

The negative effect of increased acidity is largely associated with an increase in the mobility of aluminum and manganese in the soil. With an acidic reaction, the solubility of aluminum and manganese compounds increases, and their increased content in solution has a harmful effect on plants.

Clover, alfalfa, winter wheat and rye (during overwintering), beets, flax, peas, buckwheat, and barley are especially sensitive to the increased content of mobile aluminum. These crops suffer when its content in the soil exceeds 2-3 mg per 100 g. With a high content of mobile aluminum and iron in acidic soils, they bind the assimilable forms of phosphorus with the formation of insoluble and inaccessible to plants phosphates of sesquioxides, as a result of which the nutrition of plants with phosphorus deteriorates ...

In acidic soils, the mobility of molybdenum decreases, it passes into poorly soluble forms, and it may not be enough for the normal growth of plants, especially legumes. In acidic, especially sandy and sandy loam soils, there are little digestible compounds of calcium and magnesium; in addition, the acid reaction makes it difficult for them to enter the plant, therefore, nutrition worsens with these important elements.

Influence of lime on the properties and nutrient regime of the soil

When lime is added, free organic and mineral acids in the soil solution are neutralized, as well as hydrogen ions in the soil absorbing complex, i.e., the actual and exchange-acidity is eliminated, the hydrolytic acidity is significantly reduced, and the saturation of the soil with bases increases. Eliminating acidity, liming has a multifaceted positive effect on the properties of the soil, its fertility.

Replacement of absorbed hydrogen with calcium is accompanied by coagulation of soil colloids, as a result of which their destruction and leaching decrease, and the physical properties of the soil improve - structure, water permeability, aeration.

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

As a result of acidity reduction and improvement physical properties soil under the influence of liming increases the vital activity of microorganisms and their mobilization of nitrogen, phosphorus and other nutrients from soil organic matter. In limed soils, the processes of ammonification and nitrification are more intensive, nitrogen-fixing bacteria (nodule and free-living) develop better, enriching the soil with nitrogen at the expense of air nitrogen, as a result of which nitrogen nutrition of plants improves.

Liming promotes the conversion of aluminum and iron phosphates, which are difficult to reach for plants, into more accessible calcium and magnesium phosphates. During liming, potassium of sparingly soluble minerals more intensively passes into more mobile compounds, and potassium absorbed by the soil is displaced into the solution, but its absorption by plants due to antagonism between K cations+ and Ca 2+ does not increase. Liming affects the mobility in the soil and the availability of trace elements for plants. After adding lime, molybdenum compounds are converted into more digestible forms, and the nutrition of plants with this element is improved. On the other hand, the mobility of boron and manganese compounds during liming decreases, and plants may lack them. Therefore, on limed soils, it is effective to apply boric fertilizers, especially for crops that are demanding on boron - sugar and fodder beets, clover, alfalfa, buckwheat, onions, etc. When lime is applied, the soil is enriched with calcium, and when using dolomite flour - and magnesium; the need of plants for these elements is fully met. Improving plant nutrition with nitrogen and ash elements is also associated with the fact that on limed soils, plants develop more powerful root system able to absorb more nutrients from the soil.

Determination of the need for liming soils and the rate of lime

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

The need for liming the soil can be tentatively determined by some external signs. Acidic strongly podzolic soils usually have a whitish hue, a pronounced podzolic horizon, reaching 10 cm or more. The increased acidity of the soil and its need for liming are also indicated by poor growth and strong loss of clover, alfalfa, winter wheat during overwintering, the abundant development of weeds resistant to acidity: sorrel, pikulnik, field coryza, creeping buttercup, white grass, pike.

The need for liming soil with sufficient for practical purposes can be determined by the exchange acidity (pH of the salt extract). At a pH value of the salt extract of 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 of more than 5.5, there is no need. The value of soil acidity is an important, but not the only indicator characterizing the need for liming in soils. It is also important to take into account the degree of saturation of the soil with bases (Y) and its mechanical composition. Taking these three indicators into account, the degree of soil need for liming can be established much more accurately (Table 1).

1. Assessment of the degree of need for liming depending on the properties of the soil (according to MF Kornilov) The need for liming soils

Mechanical composition of soils

The need for liming soils

absent

Heavy to medium loamy

Light loamy

Sandy and sandy

Swampy peaty and torus

When liming is carried out, in addition to soil properties, it is also necessary to take into account the peculiarities of cultivated crops in crop rotation.

For field crop rotations with a low specific gravity of flax and potatoes, as well as crops sensitive to acidity (vegetables, fodder, etc.), the sequence of liming coincides with the grouping of soils according to the degree of need for it, indicated in Table 21. Strongly needed soils are lime first of all , moderately needy - in the second and weakly needing - in the third place. In crop rotations with a high specific gravity of flax and potatoes, weakly needed soils do not lime, and in crop rotations with crops sensitive to acidity, first of all, it is necessary to lime not only soils strongly, but also moderately needed.

Lime rates depend on the degree of soil acidity, their mechanical composition and the characteristics of cultivated crops.

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

Approximate norms of lime can be determined by the pH value of the salt extract. Depending on these indicators, VIUA recommends adding the following lime rates to sod-podzolic soils containing no more than 3% organic matter (Table 2).

2. Norms of lime (CaCO3, t per 1 ha) depending on the pH of the salt extract and the mechanical composition of the soil
	salt extract pH
Sandy loam and light loamy
Medium and heavy loamy

It is possible to more accurately establish the full rate of lime by the value of hydrolytic acidity. When calculating the rate of lime (in t Ca CO 3 per 1 ha), the value of hydrolytic acidity in meq per 100 g of soil (Ng) is multiplied by a factor of 1.5. For example, the hydrolytic acidity of the soil is equal to 4 meq per 100 g of soil. Ca CO norm 3 will be 4-1.5.6 tons per hectare. The rate of specific lime fertilizers (Н) is calculated taking into account the content in them of the sum of substances neutralizing acidity (based on pure Ca СО 3 ) and the number of large particles (more than 1 mm) according to the following formula: H = (Norm (Ca CO 3 , (t per 1 ha) by soil acidity * 100 * 100) /% Ca CO 3 , in fertilizers "(100—% of particles more than 1 VM)

When setting the rate of lime for specific conditions, it is necessary to take into account the mechanical composition of the soil and the characteristics of crop rotation. On heavy soils and under crops that are very sensitive to high acidity (beets, corn, clover, alfalfa, cabbage, etc.), it is better to apply the full rate of lime, calculated by the hydrolytic acidity. On lighter low-buffer soils and for crops that are not sensitive to acidity (potatoes, lupine, etc.), the lime rate must be reduced by 1/3 - 1/2.

For better organization liming, zonal agrochemical laboratories, on the basis of agrochemical examination of soils, compile and transmit to farms cartograms of soil acidity, on which areas with different degrees of acidity and need for liming are distinguished (see Fig. 4). Periodically (after 5 years) agrochemical analyzes are repeated to clarify the previously drawn cartograms. At present, TsINAO has developed a software package "Iskra" for the compilation of design estimates for liming using a computer, which determines the areas of soils to be liming by year, the required lime rates and the general need for lime fertilizers, vehicles and machines for their application. , costs of liming and their recoupment on the farm.

Work on chemical soil reclamation on collective and state farms is carried out at the expense of budgetary state funds either by departments of Agricultural Chemistry, or by the efforts of the farms themselves.

Development of design estimates for liming acidic soils is carried out by design and survey stations for chemicalization.

Lime fertilizers

Lime fertilizers are obtained by grinding or burning hard limestone rocks (limestone, dolomite, chalk) or using soft limestone rocks and various industrial wastes rich in lime for liming.

Limestone flour is the main industrial lime fertilizer; obtained by grinding or crushing limestone. They consist mainly of calcium carbonate - Ca CO 3 , but most often dolomitized, i.e., they also contain Mg CO 3 , (up to 10-15% based on MgO). The higher the content of Mg CO in the rock 3 , the harder and more durable it is. With a high content of Mg CO 3 , (18–20% based on MgO) the rock is called dolomite, and when it is ground, dolomite flour is obtained. Lime materials containing magnesium for many crops (beets, potatoes, flax, clover, alfalfa, buckwheat, carrots, onions, etc.) are more effective than lime fertilizers that do not contain magnesium, especially on sandy and sandy loam soils poor in magnesium. When they are introduced into the soil, the negative effect of liming with full rates on potatoes and flax is eliminated or reduced.

The quality of lime fertilizers is assessed by the amount of compounds that neutralize the acidity of the soil, and by the fineness of grinding. Industrial lime fertilizers must contain at least 85% Ca CO 3, and MgCO 3 ... The finer the grinding of limestone and dolomite flour, the sooner and more completely it dissolves, the faster it neutralizes the acidity of the soil and the higher its efficiency. The most effective is limestone flour with a fineness of less than 0.25 mm. With a high content of coarse particles (larger than 1–3 mm), its efficiency sharply decreases. According to the state standard, class I limestone flour should contain no more than 5% of particles larger than 1 mm and 70% - less than 0.25 mm in diameter, its moisture content should not exceed 1.5%, and the amount of impurities should not exceed 15%.

Burnt and slaked lime.

When calcining CaCO limestones 3 turns into CaO (Ca CO 3 = CaO + CO 2 ,), we get burnt (lumpy) lime. When it interacts with water, calcium hydroxide is formed [CaO + H 2 O = Ca (OH) 2 2 is equal to 1.35 t Ca CO 3 ... Fluff is a fast acting lime fertilizer. Its efficiency in the first year after application can be higher than Ca СО 3 , but over the years, their effect levels off.

Of great importance for liming acidic soils are loose calcareous rocks that do not require grinding: calcareous tuffs, or key lime, drywall, or lake lime, marl, peat tuffs, natural dolomite flour.

Various industrial wastes can also be used as lime fertilizers: shale ash, blast-furnace and open-hearth slags, defecation (defecation mud), etc.

Timing and methods of adding lime

Lime has a long-lasting effect. It has been established that the full rate of lime can have a positive effect on the yield of agricultural crops during two rotations of a 7-8-field crop rotation, a half rate - no more than one rotation (6-7 years). Over time, after the introduction of lime, a gradual increase in soil acidity occurs again (especially quickly on low-buffer soils and with the systematic use of physiologically acidic fertilizers in high doses) and there is a need for re-liming. The frequency and efficiency of repeated lime application depends on its rate during the initial liming and the provision of the farm with mineral fertilizers. With liming at half rates and intensive use of mineral fertilizers, the frequency of liming becomes more frequent, and the efficiency of re-applying lime is quite high. The need for re-liming is established on the basis of data from the agrochemical analysis of the soil (determining the degree of its acidity) and the calculation of the calcium balance based on the results of lysimetric experiments.

The effectiveness of liming depends to a large extent on the even application of lime into the soil and thorough mixing it with the soil. The lime should be well crushed and evenly dispersed over the soil surface prior to incorporation, which is best achieved with lime seeders and spreaders. Dusty lime fertilizers - limestone flour, shale ash, cement dust and dusty waste from the metallurgical industry are introduced by cement trucks or other machines of this type. It is necessary to use such a method of lime embedding, which ensures good mixing of it with the entire arable layer of soil - under a plow from autumn for autumn plowing or in spring for plowing autumn plowing, best of all together with organic fertilizers- manure, peat, compost. When using phosphate rock, it is better to apply it for plowing plowing, and lime for plowing or cultivation. From an organizational and economic point of view, liming is most convenient in steaming fields. In crop rotations with clover, the cover crop is the object of priority liming. In tilled crop rotations, lime must first of all be applied under corn and root crops, and in vegetables - under cabbage and beets or under their predecessors.

On natural hayfields and pastures, lime is applied superficially. The liming of acidic soils sharply increases the productivity of forage lands, while not only increasing the yield, but also improving the composition of the grass stand, the fodder value of hay and pasture fodder. Liming is one of the main activities in the lining and creation of cultivated pastures on acidic soils. Lime is brought in for plowing when carrying out cultural and technical works; you can bring it under cultivation.

Liming efficiency

Under the influence of liming, the use of soil nutrients and fertilizers by plants increases and the yield of agricultural crops increases significantly. On the basis of numerous experiments, it has been established that this method on medium- and strongly acidic sod-podzolic soils increases the yield of winter wheat by 3-7 centners, rye, spring wheat, barley by 2-5, clover hay by 8-15 and more, sugar, fodder beets and cabbage by 40-100, corn (green mass) by 30-70, potatoes by 10-20 centners per hectare. With liming of strongly acidic soils, the yield increases to a greater extent than medium and weakly acidic ones, and the yield increases increase with an increase in the rate of lime.

Lime slowly dissolves and interacts with the soil, its effect manifests itself gradually, so the effect of liming reaches a maximum in the second or third year.

When the full dose is applied, the positive effect of lime on the crop appears within 8-10 years. During this time, each ton of lime gives a total increase in the yield of all cultivated crops, equal to 12-15 centners per hectare in terms of grain.

Liming is the main condition for the effective application of fertilizers on acidic soils. The effectiveness of mineral and organic fertilizers on limed soils increases significantly. A positive effect is observed from the joint application of lime and manure. Experiments show that on acidic podzolic soils, the combination of liming with the introduction of moderate rates of manure in most cases gives the same or higher increase in crop yields as a double rate of manure on unlimed soil.

The effectiveness of mineral fertilizers on strongly and moderately acidic soils during liming increases by 35-50%, and weakly acidic - by 15-20%. The yield gains from the combined application of lime and mineral fertilizers are usually higher than the sum of the increases from their separate application.

Liming acidic soils not only increases the yield and efficiency of fertilizers, but also provides a significant economic effect.

The economic efficiency of liming is determined by the amount of costs for its implementation and the cost of additional products obtained from lime during the entire period of its operation.

The cost of using lime fertilizers depends on the materials used, the rate of lime, the type and distance of transportation, storage and application technology. Costs for the use of 1 t of Ca СО 3 when transporting up to 500 km railroad and up to 25 km by road average from 8.5 rubles. for standard limestone flour up to 10-36 rubles. for non-standard fertilizers. In the structure of liming costs, the largest share of costs falls on transportation, handling and fertilization. Yield gains from liming and the economic efficiency of this technique can vary widely depending on the degree of soil acidity, lime rates and the composition of crop rotation. The greatest net income from liming of acidic soils and the recoupment of costs are provided in crop rotations with the presence of crops that strongly respond to liming. The results of many field experiments show that on highly and medium acidic soils, the costs of liming are compensated for by the cost of an additional harvest of grain in 1-2 years, fodder crops in less than a year, and potatoes and vegetables in three to five times in a year. ... On slightly acidic soils, the payback time increases by 1.5 times.

Many crops that grow in our gardens and vegetable gardens react negatively to acidic soils. Those soils are considered acidic if their pH does not exceed 5.5. The response to such conditions is usually a deterioration in growth, a weakening of the plant, and a lack of fruiting. If you are just faced with such a problem on your site, do not rush to get upset. Now we will talk about what is liming of the soil in the country: norms, terms, how to carry it out?

What is the meaning of liming the soil?

Liming acidic soils with lime will provide plants comfortable conditions for growing. In an acidic soil environment, such useful trace elements as calcium, magnesium, phosphorus and potassium, useful for growth, are very poorly supplied to plants. Even if, at the same time, regular and high-quality feeding is carried out, summer cottage crops still do not receive adequate nutrition, which is why they develop incorrectly. Some soil additives allow you to raise the pH level.

Soil liming is divided into two types: main (reclamation) or repeated (maintenance).

Primary liming is carried out on those soils that are initially acidic. Over time, lime is washed out of the soil composition, which leads to the need to repeat the procedure and replenish the compositions that increase the pH level. The acidity of the soil is reduced by supporting liming every 4-5 years.

The following substances reduce acidity well: wood ash, crushed chalk, peat ash, lime or dolomite flour, slaked lime. According to the norms, lime cannot be applied at the same time as fertilizers, which include manure. As a result, insoluble compounds harmful to plants can form in the soil.

Optimal timing liming acidic soils

Initially, liming the soil on the site is recommended at the very stage of laying the garden. It is advisable to choose the autumn period for the procedure. Limestone compositions are applied simultaneously with organic fertilizers at the moment when the earth is dug up. It is imperative to dig it up, since all useful substances can remain on the surface, and not in the composition of the soil.

Liming is also allowed in the spring. In this case, the procedure is performed three weeks before the sowing of vegetables is scheduled. If you choose winter for liming, then it is allowed to sprinkle dolomite flour directly on the layer of snow cover, provided that it does not exceed 30 cm.

Soil liming rates

The acidity level is indicated by the pH value. Its meaning means:

3-4 - acidic soil;
- 5-6 - slightly acidic;
- 6-7 - neutral;
- 7-8 - alkaline;
- 8-9 - strongly alkaline.

Application rates based on 1 kg per 1 sq. M. for soils of different acidity:

Very acidic (pH less than 4) - 0.5-0.6 kg
- strongly acidic (pH = 4) - 0.4-0.5 kg
- acidic (pH 4-5) - 0.3-0.4 kg
- relatively acidic (pH 5-6) - 0.2-0.3 kg.

Novice gardeners and summer residents ask themselves which lime is best for the soil?

Firstly, it is imperative to mix the applied composition with the earth, and therefore it is optimal to use powdered additives.

Secondly, quicklime must be quenched, using 1.5-2 buckets of water for every 50 kg.

When applying ground limestone to clay and loamy soils, it is necessary to fill up 1 sq. 600 grams of fertilizer, and when applied to sandy soils - 350-400 grams of powder. In the soil with a pH of 4-4.5, it is necessary to apply 250 g of fertilizer, and at a pH of 4.6-5.0 - at least 300 grams per 1 sq. Volumes given are only suitable for limestone. For other components, the amount is calculated as follows: the rate indicated for limestone is multiplied by 100, the resulting number is divided by the percentage of lime characteristic of the following substances:

For dolomite flour - 95%
- for crushed chalk - 90%
- for lake lime - 76-80%
- for peat ash - 40-50%.

Gypsum is not used for liming. Although it contains the lime we need, when it gets into the soil, it only crystallizes the salts present in it. Therefore, it can only be used initially when working on highly saline soil compositions. On average, experts recommend using 1 kg of slaked lime for each kilogram of mineral fertilizer applied.

How to liming soil for different crops?

On acidic soils, plants such as heather, medicinal plant, creeping buttercup, marsh plant wild rosemary, sorrel, field coryza, rush, pike. If there are too many of them in fields, plots or roadsides, then the soil there is too acidic. However, any plants feel comfortable at different levels of acidity. The optimal pH is:

For plums - 7
- for pears and apple trees - 6.5
- for currants - 6
- for gooseberries and raspberries - 5.5
- for strawberries - 5.3.

When liming potatoes, lime is applied in full volumes, and not in partial ones, but the fertilizers must contain metallurgical slag or magnesium.

Weakly sensitive to acidic soil are oats, millet, radishes, rye, carrots, tomatoes. They respond well to full dose liming. Sugar and fodder beets, cabbage, and alfalfa are considered extremely sensitive to acidity. They cannot withstand even slightly acidic soil, therefore they very actively respond to the addition lime compositions.

Soils with neutral acidity are suitable for cucumbers, onions, lettuce, legumes, corn; the annual sunflower plant, barley and wheat feel good on them. They grow well at neutral pH, but have an extremely positive attitude towards liming.

Strong acidity is preferred by seradella, lupine, and Chinese tea bush. They do not tolerate the introduction of lime, as a result of which the yield is significantly reduced.

Liming should not be applied without introducing organic matter into the soil, as this can cause complete soil degeneration. Therefore, this method is used exclusively where the level of acidity is really increased.

Every experienced farmer knows that in order to get a good harvest from his site, it is necessary to take into account the acidity of the soil. The initial acidity depends on the type of soil, but agrotechnical work leads to a gradual decrease in this parameter. Therefore, it is imperative to periodically engage in liming the earth.

Why does the acidity of the soil increase?

The acidity (pH) of a soil is a measure of the balance of hydrogen ions in the soil. To determine it, a scale from 1 to 14 units was adopted, in which pH = 7 corresponds to neutral soils, for acidic soils this indicator is lower, and for alkaline soils it is higher.

A decrease in the pH level occurs under the influence of the following factors:

• abundant rainfall and watering, which wash salts into deeper layers of the soil, in addition, and the water itself can be acidic;
• introduction of peat, compost, fresh manure, sawdust, rotted needles;
• cultivation and incorporation into the soil of some green manure, such as mustard, rapeseed, oats, rape;
• constant use of mineral fertilizers such as ammonium nitrate, ammonium sulfate, potassium sulfate.

The scale indicates the initial acidity characteristic of the main types of soils

What signs indicate increased acidity

In plants that are not adapted to growing on acidic soils, with a decrease in pH, the nutritional regime is disturbed, they poorly assimilate nitrogen, phosphorus, potassium and other elements. Plants grow worse, their yield decreases. Weeds help to determine the acidity of the site: wheatgrass, sow thistle, dandelion, plantain, heather grow well on weakly acidic and acidic soils.

More precisely, the pH value is determined using laboratory analysis. The simplest and most affordable means for conducting it on your own is a set of litmus papers, which can be purchased in specialized stores. From the investigated area, soil is taken to a depth of about 12 cm, mixed with water in a ratio of 1: 5. It is better if the water is distilled. When the earth settles, a litmus paper is placed in the solution, after the color change, a comparison is made with a template.

Using such a kit, you can determine the acidity of the soil.

Video: how to determine the acidity of the soil at home

Liming the soil in autumn

Liming - effective method raising the pH level... The most suitable period for it is autumn after harvesting from the beds. The time of the work is chosen so that the earth is wet, but it can be easily loosened with a rake.

For liming, you can use various substances containing calcium. These include:

• limestone (shell rock) - sedimentary rock with a high content of calcium carbonate;
• chalk is a type of limestone;
• quicklime - calcium oxide;
• slaked lime (fluff) - calcium hydroxide, working with the substance requires increased safety measures;
• dolomite flour - fertilizer obtained from carbonate rocks by grinding;
• cement - construction material containing a significant amount of limestone.

How much lime to apply depends on the type and acidity of the soil.

Table: application rates of slaked lime (dolomite flour) in g / m 2

Crushed lime or other substance is evenly scattered over the soil surface and embedded in the soil at a shallow depth. Closing can be omitted, but in this case, the efficiency of the work is somewhat reduced.

Lime is easily incorporated into the soil with a rake

Video: deoxidizing the soil

How often liming should be carried out depends on the natural conditions and the type of soil. If your site is located on the site of a peat bog, the region is characterized by high humidity and a lot of rain, then lime application is carried out at intervals of three years. For soils with low water permeability (clay and loamy soils), this interval can be seven years.