How to use superphosphate fertilizers. Double superphosphate: application in the garden, composition
The use of superphosphate fertilizer saves gardeners from many problems. After all, sometimes even the most zealous gardeners have problems with plants - either the leaves wither, or their shape and color change. This may indicate that there is not enough phosphorus in the soil - an essential substance for the normal growth and development of crops.
Phosphorus is needed to ensure metabolic processes in the plant, its nutrition and energy saturation. The yield directly depends on the degree of saturation of the soil with this chemical element. And superphosphate is made just on the basis of phosphorus and nitrogen. It also includes a complex of trace elements and minerals. So, this fertilizer is incredibly useful and often simply necessary for growing cultivated plants.
How to feed with superphosphate?
In order to achieve the best results, it is important to read the instructions for use of superphosphate fertilizer. Depending on the specific plants, you need to select the proportions and method of applying fertilizer. Usually all this is specified on the packaging.
It is also important to remember that fertilizer does not have the same potency in acidic soil, so you need to make allowances for this. And in order to deoxidize the soil and give the fertilizer the opportunity to act in full force, you need to add wood ash or lime mixture to it in the amount of 500 ml of lime or 200 g per square meter earth. And only a month after that you can use superphosphate - before the earth has not yet completed the process of deoxidation.
When you are ready to feed, you just need to pour the granules into the soil. This will provide an excellent growth rate and development of plants that need a lot of sulfur. Among them are potatoes, turnips, flax, radishes, onions.
The use of double superphosphate
The so-called double superphosphate must be applied to the soil in early spring, before the start of landing work or from the fall, as soon as the harvest was harvested. This is necessary so that the fertilizer has time to settle into the soil.
Instructions for use of double superphosphate:
- for uniform application, it is better to use a grain seeder;
- it is better to apply superphosphate before sowing crops;
- manual spreading of granules does not have the same effect, since the fertilizer must be closer to the root system of the plants;
- to improve the effect, you can use double superphosphate along with nitrogen-potassium, potash fertilizers introduced in spring and autumn.
Superphosphate application rates: 30-40 g of double superphosphate is applied to seedlings of greens and vegetables per square meter, 600 g per square meter are applied to the soil for feeding trees in autumn, 100 g per square meter of land is applied to seedlings in a greenhouse, in holes 4 g of fertilizer is poured with potatoes.
Why and how to dissolve superphosphate in water?
Sometimes gardeners pre-dissolve superphosphate granules and only then apply it to the ground. This provides an accelerated process of its penetration to the roots of plants.
To dissolve it in water, you need to achieve high temperature reaction, for this, the granules are poured with boiling water. 
There is no need to be afraid that phosphorus will lose its properties - they all remain. But the fertilizer takes an easily digestible form.
In order to prepare the mixture, you need to take a container, stir the granules in the proportion of 20 tablespoons per 3 liters of water, put them in a warm place for a day and mix from time to time. The suspension will look like cow's milk.
The resulting solution is added to water for irrigation at the rate of 150 ml per 10 liters. For best result also pour 20 ml nitrogen fertilizer and 0.5 kg wood ash. The resulting fertilizer is very important for spring feeding roots. At the same time, useful substances enter the plants gradually, and their effect persists for several months.
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Physical and chemical properties
Superphosphate is a friable powder or granular product. gray color 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 also as fire retardant coating 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 Intensive processes of fixation of soluble phosphates on the surface of soil colloids, which are rich in sesquioxides, are characteristic.
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 yields 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.
As is known, as the main dressings of cultivated plants on various stages their development uses nitrogen, potash and phosphorus fertilizers. Among the latter, superphosphate is especially well known.
Description and characteristics
Superphosphate - is one of the most popular mineral fertilizers among gardeners. phosphate fertilizers. Phosphorus is contained in it mainly in two forms: phosphoric acid HPO3 and monocalcium phosphate Ca(H2PO4)2. Also in the composition there is gypsum, aluminum and iron phosphates, silicon dioxide, various fluorine compounds.
The main advantage of superphosphate is the phosphorus oxide present in its composition. Its aqueous solution is easily and quickly absorbed by various cultivated plants. The absorption of this component deteriorates at low temperatures.
Manufacturers additionally add compounds of nitrogen, sulfur, calcium, boron and molybdenum to the composition of superphosphate. Fertilizer is produced from phosphorites of natural and artificial origin.
Phosphorus is responsible for energy exchange cellular level. With a lack of phosphorus, the plant begins to absorb other micro and macro elements obtained from the earth worse.
Phosphorus deficiency symptoms:
- plant leaves turn blue (purple, green or yellow tint may be present);
- on the lower leaves appear dark spots irregular shape copper or purple hues;
- leaf petioles turn purple;
- the affected leaves curl, dry up and fall off;
- overall growth stops.
Very often, young seedlings suffer from a lack of phosphorus (especially those planted in the winter months). In this situation, in small concentrations, top dressing with superphosphate is performed already 10 days after picking.
The effect of phosphorus on plants:
- the functioning of the root system as a whole improves;
- the growing season increases (plants age more slowly);
- culture begins to bear fruit earlier;
- the duration of the fruiting period increases;
- the quality of the harvest is noticeably better.
Today on the market you can find superphosphate in various forms.
Simple superphosphate (monophosphate)
Practically non-caking gray powder with a pronounced acid odor. It contains:
- phosphorus compounds - up to 20%;
- nitrogenous compounds - up to 8%;
- sulfur compounds - up to 10%;
- calcium sulfate (in the form of gypsum).
This is the most ineffective variety of superphosphate. However, due to its low cost and better water solubility, this mineral supplement is still quite popular.
Often, monophosphate is used to improve vegetable top dressings and composts.
Granular superphosphate
This variety is made from simple superphosphate, which is pre-moistened, pressed and rolled into small granules up to 4 mm. The proportion of phosphorus compounds can reach up to 50%, calcium sulfate - up to 30%.
Granular superphosphate is better stored and more convenient to use. Granules dissolve more slowly in the soil, so their action is more prolonged (up to 2-3 months).
This top dressing is most good for bulbs, legumes, cereals and cruciferous crops.
Double superphosphate
This fertilizer is more concentrated (the proportion of phosphorus compounds is up to 50%), which means that it contains fewer additional impurities. In addition, the proportion of nitrogen in its composition is increased to 15%.
Double superphosphate is produced in granules. Fertilizer is applied to the soil either in the fall when digging, or in early spring. Also, at different times, cultures experiencing phosphorus starvation are fed with a solution based on it at different times.
It can be applied to all types of plants and on any soil. Good compatibility with potassium supplements.
Dosage
The most important component of success is the choice of the correct dosage. Before use, carefully read the instructions for reverse side packaging.
| Application rates of double superphosphate | ||
| culture | Priority deposit | Application rules |
| Potato |
During autumn or spring digging:
|
5 g per hole when planting and 15-20 g per 1 m2 when top dressing. |
| Vegetables | 10 g per line m. in rows when sowing or 5 g per hole when planting seedlings; 15-20 g per 1 m2 when feeding. | |
| Fruit trees | 300 to 500 g per landing pit put when planting a seedling; 40-60 g are applied to the area trunk circle spring; 40-60 g in the area of the near-stem circle after flowering. | |
| berry bushes | From 80 to 180 g are placed in the planting hole when planting a seedling; 20-30 g is applied to the region of the near-stem circle in the spring; 20-30 g in the area of the near-stem circle after flowering. | |
| Strawberry wild-strawberry | ||
| Flowers | 5 g per hole when planting seedlings and 5 g under a bush or 10-15 g per 1 m2 when feeding. | |
For a balanced feeding of vegetables and leafy greens during autumn or spring digging, the following is added to the soil:
- monophosphate - from 60 to 80 g;
- double superphosphate - from 30 to 40 g.
In greenhouses and greenhouses, it is preferable to use double superphosphate. Be sure to add 3-4 g of powder to the planting holes when planting seedlings.
To prepare a working solution of 100 g of dry fertilizer, pour 1 liter of water and put on fire for half an hour. When the composition has cooled, strain it through cheesecloth. Dissolve 100 ml of the resulting solution in 10 liters of water (this amount is enough to feed 1 m2 in a greenhouse or on a plot).
It is worth noting that superphosphate reveals all its effectiveness only on neutral and alkaline soils. In acidic soil, phosphorus actively combines with aluminum and iron. Plants cannot absorb such compounds.
