Ammonium superphosphate is used as top dressing. Physical and chemical properties

Top dressing of tomatoes with superphosphate is used to increase the yield of fruits. Fertilizer is mainly used for those vegetables that have been planted in a greenhouse or greenhouse.

Superphosphate is a fertilizer that contains phosphorus, nitrogen, sulfur and calcium sulfate. The use of this type of fertilizer slows down the aging process of plants, improves the taste of fruits, nourishes root system. There are two types of phosphate fertilizers:

1. Simple superphosphate. Good for sandy and podzolic soils. Simple superphosphate is mainly fed with legumes and cereals.
2. Double superphosphate. In him increased content phosphorus and sulfur, and therefore it is suitable for all kinds of soils and plants.

Phosphate fertilizer is different in that it has long term actions. The plant takes exactly as much phosphorus from the soil as it needs. Therefore, the effect of fertilizer can stretch for years. Experienced farmers fertilize the soil either in early spring, or in the fall, so that the phosphorus has time to "disperse" in the soil and the soil is ready for planting. Many people use phosphorus fertilizer to feed seedlings after planting.

How to determine that tomato seedlings need to be fed? You need to pay attention to the leaves of tomatoes. If they turn dark green or blue, then the tomato lacks phosphorus. Also, a rusty tint may appear on the leaves, which also indicates a lack of elements. Sometimes only back side leaf acquires purple, which may indicate hardening of seedlings. In these cases, the use of superphosphates is simply necessary.

Phosphorus-potassium fertilizers (video)

Extract from phosphate fertilizer

Phosphorus itself, due to its chemical composition very difficult to dissolve in water. But at the same time, it is in liquid state it best fertilizes the root system of tomatoes. You can prepare an extract from superphosphate using boiling water.

Pour the fertilizer with boiling water, put in a warm place and stir often. The granules will dissolve in a day. Gardeners recommend dissolving 20 tbsp. l. for 3 liters of water. It should be understood that the solution will not become completely liquid. It has a consistency similar to full-fat cow's milk. The resulting extract is the base for the preparation of the main fertilizer.

Application of phosphate fertilizers

Tomato seedlings grown at home, when planted in greenhouses, often look weak and pale. In this case, you can use superphosphate immediately when planting tomato seedlings. Pour 10-15 g of fertilizer into each well.

After transplanting a tomato, you can use an aqueous solution of mullein. In this case, it is important to observe the proportions of the preparation of the solution. For every 10 liters of water, there is 1 liter of mullein. Dissolve humus in water, add 50 g of ash and 30 g phosphate fertilizer. Add to the tip of a knife boric acid and manganese. The resulting composition is used to feed a tomato from the following calculation: at least 0.5 liters of solution should go to each bush.

Experts advise to make 2 such dressings. Moreover, exactly 10 days must pass between them. It is important not to overdo it and not to contribute too much various fertilizers. Excess nitrogen and phosphorus can lead to the fact that the tomato will not bloom and bear fruit.

If too much superphosphate was added, this can be corrected as follows:

1. Do not water tomatoes for a week. During the same period, the daily air temperature should be kept at +24 ... +26 ° С.
2. Do root dressing. To do this, dilute 3 tbsp. l. extracts of superphosphate in 10 liters of water. Water the tomatoes with the resulting composition at the rate of 1 liter per bush.

The chemical formula of superphosphate: (CaH2PO4) 2 x H2O + 2CaSO4 x 2H2O

Simple superphosphate contains phosphorus in a water-soluble form and is available as a loose powder or granules. gray color. This fertilizer is fire and explosion-proof. The exact amount of phosphorus must be indicated on the packaging bag.

Why do plants need phosphorus?

Most phosphorus is found in reproductive organs and young plant tissues, where intensive synthesis processes take place. But the largest consumption of phosphorus by plants occurs during flowering and fruiting. Typical sign deficiency of this element: weak fruit set with normal pollination of flowers, as well as shedding of unripe fruits.

The introduction of phosphorus into the soil provides a number of advantages, some of which are immediately noticeable and tangible:

• speeds up germination
• stimulates the development of a powerful root system
• stimulates flowering
• slows down the aging of plants
• improves head formation in cabbage
• improves the taste of fruits, berries, tubers and root crops (in berries and fruits, sugar content increases, in seeds - oils, in tubers - starch)
• reduces the amount of nitrates in fruits
• phosphorus in combination with nitrogen contributes to a better absorption of magnesium by plants
• increases resistance to viruses and diseases

From vegetables, potatoes, any cabbage, carrots, cucumbers have the greatest need for phosphorus.

The average need for tomatoes, peppers, eggplant.

Below dependence on phosphorus in beets, onions, radishes, lettuce.

If the summer turned out to be dry, then with a lack of moisture, the need for phosphorus increases.

Simple superphosphate

Simple powdered superphosphate contains practically nothing but phosphorus oxide - it contains 16-20%. But the powder is quite hygroscopic, caking and not very convenient to use (it is difficult to find a dry place in the garden and monitor the tightness of the container). The only advantage is that the price of superphosphate in powder is very low. However, on acidic soils superphosphate powder passes into a state indigestible for plants. In addition, the powder has fuller contact with soil particles and less contact with plant roots. And, as you know, P2O5 ions are inactive in the soil, and plants absorb only those that are within a radius of the sucking root of no more than 1 ml.

Therefore, gardeners often use granular superphosphate, with a particle size of about 3-4 mm, which also contains other nutrients. In the soil, it dissolves more slowly, but is more available to plants.

The composition of simple superphosphate: nitrogen 6%, phosphorus 26%, calcium 8.6-12.1%, magnesium 0.5%, sulfur 8-10%. It is obtained from powder, rolling into granules. They are not hygroscopic and do not cake.

Double superphosphate

Double superphosphate contains almost twice as much phosphorus: 42-46% in an easily digestible form, nitrogen up to 15%, 6% sulfur, does not contain gypsum. Its formula is Ca(H2PO4)2H2O, phosphorus in the form of calcium monophosphate.

Double superphosphate is available in granular form, it is highly soluble in water. Its price is somewhat higher than that of simple superphosphate, but in the end it is more profitable.

Superphosphate enriched

In addition to simple and double superphosphate, there are phosphate fertilizers with additives:

• boron superphosphate (water-soluble boron 0.2%), double with the addition of boron up to 0.4%,
• manganese enriched granular superphosphate with manganese content 1.5-2%
• zinc superphosphate contains about 0.1% zinc additive

Instructions for use

Superphosphate is used for the main, pre-sowing application, during sowing and as top dressing for all crops on all types of soil: it is used for top dressing of any vegetables, berries, fruits, fruit trees and shrubs, ornamental flowers and plants on cultivated and uncultivated soils.

Fertilizer is applied to the soil in autumn or early spring, so that phosphorus has time to “disperse” through the soil. In addition, it is recommended to water plants that lack phosphorus with an aqueous solution of double superphosphate 1-2 times a season. Like simple superphosphate, it is suitable for all plants and all types of soil.

Application rate of superphosphate (simple)

• On cultivated (already cultivated) soils for any crops, when applied for digging in autumn or spring - the norm is 40-50 g / sq. m
• On uncultivated soils (abandoned gardens, overgrown with weeds) for any crops when applied for digging in autumn or spring - the norm is 60-70 g / sq. m
• Under fruit trees spring planting(in a planting pit with mixing with the ground) - the norm is 400-600 g / tree
• Under raspberries when planting bushes, applying superphosphate 80-100 g per pit
• Under currants and gooseberries, when planting bushes, the introduction of superphosphate 25-30 g per 1 sq. m
• Under coniferous trees and shrubs when planting in each hole, the norm is 60-70 g of superphosphate
• Under already planted fruit trees, as top dressing in spring and after flowering - the norm is 40-60 g per 1 sq. m near the trunk circle
• Under potatoes, when planting, superphosphate is added to the hole and mixed with the ground - the norm is 3-4 g per plant
• Under vegetable seedlings, when sowing root crops (carrots, beets, radishes) as top dressing - the norm is 20-30 g / sq. m
• Greenhouse plants (vegetables, greenhouse flowers, cut flowers) superphosphate is applied for digging the soil along with potash and nitrogen fertilizers- the norm is 40-50 g / sq. m

Application rate of double superphosphate

• On cultivated (already cultivated) soils for any crops, when applied for digging the soil in autumn or spring - the norm is 15-20 g / sq. m
• On uncultivated soils (abandoned gardens, overgrown with weeds) for any crops when making soil for digging in autumn or spring - the norm is 25-30 g / sq. m
• Under already planted fruit trees, as top dressing in spring and after flowering - the norm is 10-15 per 1 sq. m near the trunk circle
• Application in early spring for digging or for top dressing after flowering
• When sowing vegetables, flowers and ornamental shrub 2-3 g of double superphosphate per linear meter
• When planting seedlings of vegetables and flowers - the norm is 0.5-1 g per plant
• How to feed vegetables, flowers, ornamental plants- the norm is 10-20 g per 1 sq. m of land (scatter, fence)
• As a top dressing of vegetables, flowers, ornamental plants in the form of a solution - the norm is 20-30 g per 10 liters of water (dissolve, pour)
• Greenhouse plants (vegetables, greenhouse flowers, cut flowers) apply superphosphate for digging the soil along with potash and nitrogen fertilizers - the norm is 20-25 g / sq. m of land

How to increase the effectiveness of superphosphate

Despite the fact that superphosphate is used on any type of soil, the best way to convert phosphorus into accessible forms is when the acidity of the soil solution is 6.2-7.5 pH. Minimum temperature soil for the absorption of phosphorus by the roots of plants is 15 ° C.

Phosphorus conversion mechanism after application to different types soil is different:

• on chernozems with a predominantly alkaline or neutral reaction, i.e. with a predominance of calcium salts, monocalcium phosphate can be converted into dicalcium and tricalcium phosphate.
• on acidic soils that are not saturated with bases, superphosphate precipitates in the form of aluminum and iron phosphates, which are poorly soluble and difficult for plants to access. Plant roots are unable to absorb them.

Therefore, in order to increase the effectiveness of superphosphate, you must first use ash, lime or dolomite flour.

Do this in advance, at least a month before applying phosphate fertilizers.

You also need to take into account the fact that the introduction together with superphosphate organic fertilizers(manure, humus, dung) increases the digestibility of phosphorus by plants, since hard-to-reach phosphorus is converted into an easily digestible form under the influence of organic matter.

With signs of phosphorus deficiency

If the plants have symptoms of acute phosphorus deficiency: the growth of the stem is inhibited, the leaves are small, their color is darker than expected or with a purple (purple-red) tint, the fruits form small, do not ripen well, it is necessary to urgently feed with phosphorus.

Those. add superphosphate 1 teaspoon per 1 sq. m, but spraying on the sheet is even more effective.

To do this, you need to take 1 teaspoon of superphosphate per 10 liters of water, pour boiling water and leave for 6-8 hours. Then filter the upper light fraction (discard the precipitate) into the atomizer (use a cloth filter to avoid clogging the nozzle).

Ash and superphosphate

Superphosphate can be added with wood ash. At the same time, ash should be taken no more than 8% by weight of phosphate fertilizer. If mixed more ash, the quality of superphosphate will deteriorate.

By the way, ash cannot be mixed with other phosphate fertilizers, only with granular superphosphate, simple or double.

How to make an extract from superphosphate

It is necessary to make an extract from that superphosphate, which is poorly soluble in water and boiling water - fertilizers from different manufacturers differ in quality and solubility. Double superphosphate, for example, is usually highly soluble in warm water, the sediment at the bottom of the bucket is the ballast substances used for the production of pellets.

The hood is most often used for senicating potatoes.

So, to prepare an extract from superphosphate, we proceed as follows:

1. Pour 2 kg of superphosphate into an enameled bucket, pour 3-4 liters of boiling water into it.
2. Stir occasionally until cool.
3. Let the sediment settle and pour the solution into the second bucket.
4. Pour the remaining granules (those that did not have time to dissolve) with another 3-4 liters of boiling water and leave overnight.
5. Now we mix both solutions in one bucket, bring the volume of the solution to 10 liters.
6. Filtered into a sprayer.

The resulting 20% ​​superphosphate solution is used for spraying the tops of potatoes, it is enough for 2 acres of a potato field. Senication inhibits development vegetative organs– tops, accelerates its aging. There is an outflow of photosynthesis products from leaves and stems into tubers, their growth and maturation are accelerated, and starch content increases.

Senication of potatoes in large farms allows you to increase profits ( early potatoes expensive). For an ordinary gardener, senication allows you to get stronger potato tubers - their cork tissue thickens and the tubers are less injured during harvesting, they are better stored in winter. According to agronomists, synecation can increase the yield of potatoes by 30-40%.

It is necessary to carry out senication 20-25 days before harvesting during the period mass flowering spraying tops.

What happens if you exceed the dose of superphosphate

It must be said that plants react differently to phosphorus released into the soil solution. For example, lettuce on soil too rich in phosphorus (when there is an excess of it compared to nitrogen) begins to shoot prematurely.

Almost all vegetables and grains are not sensitive to contact with superphosphate, granular fertilizers (double and single) are applied to the wells when planting seedlings or mixed with seeds before sowing.

But there are plants that are oppressed by direct contact of the seeds or root system with superphosphate - these are the seeds of corn, potatoes and sunflowers, seedlings of fruit trees and coniferous ornamental plants. They need a layer of soil between the fertilizer and seeds or plant roots and a low dose of phosphorus fertilizer. Therefore, for these plants, phosphorus is strictly dosed and must be mixed in landing pit with earth.

For all fruit and berry trees and shrubs, vegetables and flowers, a negative reaction can be expected if the application rate of superphosphate is very significantly exceeded. Since superphosphate dissolves in the soil for a long time and rarely reaches a high concentration of phosphorus salts. If this still happens, the plant's growth is inhibited, the leaves begin to dry out.

However, the root system of plants is negatively affected by impurities found in phosphate fertilizers - silicic acid, calcium sulfate, metal compounds and fluorine.

Therefore, the dose of superphosphate should not exceed the norm by more than 2 times, and any mineral fertilizer (not only phosphorus, but also potassium and nitrogen) must be isolated from the exposed root system of plants.

Superphosphate Compatibility

1. Plain superphosphate powder must not be mixed with ammonium nitrate and urea (lumps are formed), as well as lime, dolomite, chalk, sodium nitrate, calcium nitrate. Can be mixed with potassium chloride, potassium salt, potassium sulphate, ammonium sulphate.

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Physical and chemical properties

Superphosphate is a friable, powdery or granular gray product with various shades- from almost white to dark gray. Dark gray superphosphate contains some liquid phase.

Application

Agriculture

Simple superphosphate is used as a fertilizer for all crops on all types of soil.

Superphosphate brands registered and approved for use in Russia as a fertilizer are in the table on the right.

Industry

Simple superphosphate is used in small quantities in the yeast and sugar industries, and as a fire-retardant coating for wood.

Behavior in soil

The mechanism of behavior of superphosphate depends on the properties of the soil.

Phosphoric acid of superphosphate, when applied to the soil, can turn into a form that is difficult for plants to access.

On chernozem soil types with an alkaline or neutral reaction, with a content of calcium carbonate or calcium absorbed by the soil complex, monocalcium phosphate can turn into dicalcium and tricalcium phosphate.

Acidic soils that are not saturated with bases precipitate superphosphate in the form of aluminum and iron phosphates, which are poorly soluble in a slightly acidic environment and are difficult for plant root systems:

Fe(OH) 3 + H 3 PO 4 → FePO 4 + 3H 2 O

The intensity of chemical and colloid-chemical absorption of superphosphate phosphoric acid by the soil is directly dependent on the content of mobile forms of sesquioxides in the soil.

Acidic soils are characterized by intensive processes of fixation of soluble phosphates on the surface of soil colloids, which are rich in sesquioxides.

The fixation of phosphoric acid in the soil also occurs as a result of its biological absorption by soil microorganisms.

According to the intensity of energy with which the absorption of phosphoric acid occurs, soils can be arranged in the following sequence: red soils, podzolic soils, chernozems, gray soils.

Application on various types of soil

Superphosphate is applied on all types of soils, under all crops. Fertilizer efficiency can be improved by using techniques that reduce the chemical absorption of phosphoric acid by the soil, namely: the use of granular forms, row application, local application.

Application methods

The effect of superphosphate on the crop depends on the method of its application. The main part of the fertilizer dose is applied under the plough, in combination with row application. In highly humid conditions, as well as under irrigation conditions, part of the fertilizer can be applied at.

When applying fertilizer in the main application, it is important to choose the correct placement depth. It should be carried out precisely in that layer of soil where the bulk of the roots of the fertilized crop is located. Before sowing, superphosphate is recommended to be applied to the depth of the main processing.

The effectiveness of superphosphate increases when it is applied when sowing crops in holes, nests, etc. With this method, it is better to use granular superphosphate. necessary for plants at the very beginning of their growth. Superphosphate, like other phosphate fertilizers, increases productivity and improves the quality of agricultural products (sugar content in beets increases, starchyness in potatoes, etc.). In winter crops, winter hardiness increases and maturation accelerates. Numerous experiments have established that the introduction of 0.5 centners of granulated superphosphate per 1 ha gives an increase of up to 2.5-3 centners / ha of cereals.

Receipt

Superphosphate production technology consists of three stages: decomposition of phosphorite ore with sulfuric acid, maturation and ripening of superphosphate. AT industrial production a continuous method of obtaining fertilizer is used, when the supply of ore and acid, as well as the unloading of the finished product, take place simultaneously and continuously.

Many scientists believe that in modern agriculture impossible to manage without the use of chemical fertilizer. Of course, this issue is called controversial, because in wild nature A lot of plants grow without any top dressing. But due to the intensive agricultural technology used in growing plants, all conditions were created for impoverishment. fertile soils. As a result, mineral substances had to be added to them, among which there is also superphosphate (fertilizer). The use of these substances allows you to maintain the previous fertility of the land.

The main benefits of phosphates

If the soil does not contain phosphorus salt, then it will not be able to grow and develop normally. various plants. The soil contains a huge amount of useful nutrients, which are absorbed as a result of active processing by microorganisms living in it. This applies to such a product as superphosphate - a fertilizer, the use of which is carried out only in dissolved form. This is explained by the fact that bacteria, first of all, choose liquid components for their nutrition.

As for orthophosphoric acids, they consist of a sparingly soluble salt. In some cases, their solubility index depends on environment. The earth is rich in all the elements included in the periodic table, so dissolved phosphorus compounds are bound and precipitated. This happens under the condition that in acidic soils the acid residue meets aluminum or iron ions. For this reason, they try not to add phosphorus fertilizer to the soil where woodlice and horsetail grow, since this will be of little use.

Increasing soil fertility

The role of microorganisms in the processes of phosphorus assimilation has been repeatedly described. It is important to remember that the soil cannot be made more fertile only by the introduction of fat and mineral fertilizer. First you need to start restoring the microflora of the earth, but it should be remembered that with a significant increase in the dose of the applied chemical, it can be completely destroyed.

Improving growth and metabolic processes

Thanks to phosphorus, plants are able to regulate energy exchanges for cellular level, which favorably affects the development of their root systems. With a sufficient amount of phosphorus, accelerated absorption of various fertilizers is noted. That is, plants manage to obtain a suitable amount of elements from the soil. You can find out about the lack of phosphorus by appearance plants, as their leaves turn blue-violet and general depression is observed. If this element is present in sufficient quantity, then the process of the prevalence of the absorption of nitrogenous compounds will not occur. Therefore, the risk associated with a set of dangerous nitrites is reduced in plants. Currently, they saturate all the greens that go on sale in early spring. Its cultivation is carried out in intensive ways with the addition of mineral fertilizers.

Superphosphate (fertilizer): instructions for use

On certain preparatory stages soils for growing plants use several different ways applying this fertilizer. For example:

• autumn incorporation into the soil;
• entry into spring time in furrows or holes;
• top dressing in the summer of all fruit trees;
• top dressing in liquid form;
• composting.

The use of superphosphate helps to increase the yield. The complex of trace elements allows you to accelerate the flowering process, the development of the root system and shoots. In addition, it provides protection against the occurrence of various diseases.

Autumn top dressing

It has long been known about such a technique in agricultural technology as the use of superphosphate in the process of digging the soil, carried out in autumn months. In the event that liming of the soil is planned for autumn, the use of the drug should be postponed to spring. This is explained by the fact that the chemicals contain substances with one calcium base.

The soil becomes more saturated with various chemicals due to the presence of insoluble gypsum and soluble salts in them. The superphosphate itself, the use of which we are considering, is called an acid salt, so lime is added in order to eliminate hyperacidity. As a result, the process of mutual neutralization of properties begins. This means that the land received additional salinity and funds were wasted.

It is also not recommended to add superphosphates and urea to the soil together. These compounds are called acidic, and therefore the soil will become acidic. It is best to apply fertilizers rich in potassium at the same time. If in autumn period add phosphorus and potassium, which has a chloride form, to the soil, then the soil will easily absorb both substances.

Composting

Most best use superphosphate - introduction into composts. Experts advise doing this during the aging period, because at this time the gypsum and each accompanying substance take on a form that is convenient for plant nutrition.

During warm weather, superphosphate will be well absorbed in the base of the extract. To prepare it, you need to pour the fertilizer with boiling water and leave for 24 hours. The container must be made of enameled iron or plastic. Then you need to drain all the light liquid and use it for fast top dressing which is sometimes bred.

When making the drug "Superphosphate", the instructions for use of which are indicated on the sachets, do not exceed the permissible dosage.

Chemical constituents

In superphosphate there is a mixture, which includes calcium sesquisalt and gypsum with various impurities. The basis of each component contains phosphoric acid salts found in phosphorite and minerals. All minerals are unstable to hydrochloric acid.

During chemical reactions the formation of the above products. If superphosphate is single, then it contains a small amount of acid. Most all constituent substances are occupied by gypsum, that is, the insoluble element of superphosphates. At the end chemical process the substance acquires a loose form, not subject to the appearance of lumps.

Also, in addition to single superphosphates, it is possible to obtain double superphosphates that do not contain gypsum. But in their composition there is a large number of phosphorus.

Main varieties

Modern industrial enterprises produce superphosphate fertilizer, instructions for use of which are indicated on the package, of the following types:

• Simple powder. The use of this type of superphosphate is suitable for fertilizing sandy, podzolic, sandy loamy soils.
• Plain granular.
• Double granulated. Double superphosphate has the same application as the simple one and is suitable for all kinds of soils and all plants.
• Ammonized.
• Granular, consisting of humate.

Each variety has its own area of ​​\u200b\u200buse, which can be found in the instructions.

Physiological actions of fertilizer

If plants receive a balanced diet, then they will contain the amount of substances that is necessary for normal development. As a result, it is noted:

• increase in productivity;
• improvement palatability fruits;
• increase resistance to disease;
• fast flowering;
• acceleration of metabolic processes.

If the surface of potato tubers has brown spots, and black dots appear on the beets, this indicates a lack of phosphorus fertilizer in the soil.

In particular, the effect of a sufficient amount of fertilizer at an early stage of development is noticeable. During this time, the formation of the root system occurs, so phosphorus is necessary to improve its growth. This means that at the beginning of autumn the soil should receive a certain amount of superphosphates.

If in the spring greenhouse leaves turned blue, this does not mean that the plants need phosphorus feeding. In some cases, it will be enough to simply increase the temperature of the soil.

Any kind of soil top dressing can give a positive result after a few weeks. As for foliar dressings, then their action is much faster.

Almost all agricultural technologies recommend the use of superphosphate fertilizer, the use of which refers to the most effective way productivity increase. And this applies to both garden and garden and ornamental crops.

Superphosphate for flowers: application

The following scheme is used:

• 5 g of the drug is added when planting seedlings in the hole;
• 5 g of superphosphate - directly under the bush;
• 10-15 g per sq. meter when feeding.