Features of soil liming: norms, timing and requirements

2024 Author: Howard Calhoun | [email protected]. Last modified: 2024-01-02 13:48

When answering the question of which soils require liming, you need to proceed from which group of crops the plants that you are going to cultivate in a particular area belong to. The fact is that not all of them respond equally to soil pH.

The concept of liming

This agricultural technique is practiced on soils that have a pH of less than 7. As is known, in this case, in the soil-absorbing complex (SPC), in which the hydrogen ion is located, when interacting with lime materials, it is replaced by a calcium ion, which contributes to the neutralization of the environment in question.

Thus, the question of which soils require liming suggests a clear answer: acidic.

Plant groups in relation to acidity

Each plant organism has its own optimal environment in which it is convenient and comfortable to grow and develop. Therefore, soil liming is not carried out for all cultivated plants. They are acceptedsubdivided into certain groups depending on the relationship to the acidity of the soil:

• Acid-resistant environments - cabbage, various types of beets, alfalfa - respond strongly to the application of calcareous materials even on slightly acidic soils.
• Sensitive to high acidity, preferring neutral soils and responding well to the method under consideration: wheat, barley, corn, sunflower, lettuce, cucumber, onion, legumes - respond positively to soil liming with a norm of one and a half hydrolytic acidity.
• Plants that can tolerate low acidification and grow on slightly acidic soils. On medium and strongly acidic soils, liming is carried out for them with full norms. These include: carrots, radishes, tomatoes, rye, millet, oats.
• Crops under which liming should be carried out with caution, only on medium and strongly acidic soils: potatoes, flax. Excessive application of lime reduces the yield of potatoes, and the tubers are more affected by scab.
• Crops that do not like liming soils: lupine, tea bush, seradella. Can grow in highly acidic soils. Liming reduces yields.

Major crops respond positively to liming.

Lime for beets and cabbage is carried out directly in the year of their planting. Other vegetables are planted in limed areas in subsequent years.

Lime ameliorants

Soil liming can be carried out:

• slaked lime and quicklime;
• lake (garbage);
• burnt;
• limestone;
• calcite;
• cement dust;
• sugar production waste;
• dolomite flour;
• calcareous tufa;
• deposition of marl.

Lime tuffs are found in places where springs come to the surface, along the banks of various reservoirs, on the slopes of cliffs and bedrock banks. The effect is faster than ground limestone, but slower than burnt lime.

Lacustrine variety of chemical ameliorant is mined in the place of closed reservoirs that existed in this place in the past, as well as in former peaty depressions. Its action is faster than that of calcareous tuffs.

Dolomite flour contains not only calcium, but also magnesium. Its action is slower compared to calcareous tuffs, which contain only calcium. Dolomite flour is made from a mineral by grinding it to the smallest fractions. It not only normalizes the acidity of the soil, but also improves the structure of the upper fertile layer.

Marl is a limestone, which contains large amounts of impurities such as clay and sand. It is mined from deposits common in the podzolic zone.

Burnt lime can be slaked (fluff) and quicklime. Extinguishing can be done at home with water, without approaching the solution during boiling. This type of improverobtained by roasting hard limestone. One ton of quicklime or 1.5 tons of slaked lime is equivalent to 2 tons of lime meal.

The quality of lime powder is mainly determined by the quality of grinding. The smaller it is, the better the ameliorant is.

Nepheline waste, oil shale ash are used in places where the apatite industry is distributed.

If it is impossible to use special lime materials, you can use a synthetic mineral fertilizer called "Superphosphate", which, in addition to phosphorus, contains calcium in its composition. However, it is believed to be associated with the main element and sulfur, making it unavailable for regulating soil acidity.

Some suggest that gypsum materials can be used. However, this is an erroneous opinion. They are used in the opposite case, when the reaction of the medium is alkaline.

Determination of soil acidity

It can be determined visually, by the presence of indicator plants. These include, first of all, plantain, horsetail, horse sorrel, horseradish. However, they can also develop on soils that are not acidic. In addition, by their presence it is difficult to judge the degree of acidity of this type of substrate.

Therefore, the most reliable method is testing in laboratory conditions on special devices: ionometers or pH meters.

Liming terms for acidic soils

You should not be especially zealous when introducing such ameliorants. AtIn large doses, as with fairly frequent use, the access of plants to other nutrients, primarily such as potassium, magnesium, and phosphorus, is reduced. The water regime becomes more complicated, their immunity to various diseases decreases.

Scientists and researchers involved in agricultural chemistry advise to carry out liming of soils at a certain time: thoroughly once every five years. If the soil is strongly acidic, then annual application of lime is allowed, in small portions for autumn (autumn) plowing (digging).

The most effective way to apply this ameliorant, as well as any fertilizers, is in a local way. It is much more effective than the scatter. Liming for vegetables is carried out a week before planting.

Norms

In the scientific literature, it is recommended to calculate the application rates for soil liming of ameliorants based on hydrolytic acidity. The maximum dose should be 1.5 of this value, if necessary, it can be reduced to a single dose.

However, this indicator can only be determined chemically in the laboratory. Therefore, soil liming rates are set based on the pH value of a particular substrate. So, for sandy and light loamy soil, from 25 to 40 kg / weave is required, depending on its acidity level. For medium and heavy loamy substrates, the rate is increased by about 1.5 times.

When re-liming, the doses of ameliorants used are reduced by 50-65%.

Joint themuse with manure contributes to the rapid mineralization of organic matter. Decaying, manure contributes to the enrichment of the surface layer of the soil with CO_{2, which, in turn, accelerates the process of dissolution of lime materials.}

Autumn reclamation

When liming acidic soil in autumn, its chemical properties improve. The need for its implementation can also be determined by indicator plants, which include alfalfa and field larkspur. In the case of abundant growth of these plants on the soil, we can say that it has enough calcareous materials. An accurate determination of the pH of the medium is carried out using an ionometer.

Liming is carried out during the autumn work on soil preparation. During the period of emergence of shoots, lime should not be applied. Calcium, which is part of its composition, contributes to the compaction of the substrate, which can worsen the development of agricultural plants and even lead to their complete death.

During the application period there should be no precipitation, as well as stagnation of moisture on the soil surface.

Some sources indicate that it is impossible to apply lime together with organic fertilizers, although other authors write that mixing such materials with manure is allowed. It is undesirable to combine them with ammonia forms of nitrogen fertilizers.

Garden Liming

The initial measures for the implementation of these reclamation works are carried out at the stage of laying nurseries. They are also carried out in the autumn, combined with the application of organic fertilizers. Liming of the soil can also be carried out in winter by applying dolomite flour on snow, but the thickness of its cover should not exceed 30 cm.

Precautions

Like any reclamation event, soil liming must be carried out using personal protective equipment. Work is carried out in goggles, as well as in rubber gloves. Liming should not be done in windy conditions. If it is not possible to use plows or cultivators to plow lime, it must be plowed in immediately after spreading with a shovel or pitchfork.

Be especially careful when working with slaked and quicklime. If it gets into the eyes, the victim should be laid on his back and rinsed with running water. Then castor oil is instilled into the eyes or an ointment is applied, after which they go to the doctor.

In closing

In this article, we examined the process of liming acidic soils, the terms and norms for the use of chemical ameliorants. They do not need to be used for all crops, the main refueling should be carried out once every five years. It is best to apply them to the soil in the fall. On sandy substrates, it is necessary to carry out maintenance liming annually at reduced rates. Full norms are calculated by hydrolytic acidity or by pH. Precautions must be taken when working with these chemical ameliorants.