Using superphosphate to fertilize cucumbers in the garden and greenhouse

Cucumbers are unpretentious in care and undemanding to the type of soil, but on soils rich in organic matter and minerals they give a higher yield. Fertilizing this crop begins with the emergence of seedlings and ends 2 weeks before harvesting the vegetables. Among the wide variety of mineral fertilizers, one of the most popular options is superphosphate.

What is superphosphate

Superphosphate is a complex nitrogen-phosphorus sulfur-containing fertilizer. The chemical formula of simple superphosphate is: Ca(H2PO4)2*H2O + 2CaSO4*2H2O. It is obtained from phosphorites treated with sulfuric acid.

The main component in the composition is phosphorus in an easily digestible form for plants. Fertilizer is commercially available in the form of powder or granules.

Why do cucumbers need it?

At each stage of development, plants need certain substances. A macroelement such as phosphorus is vital for cucumbers: it provides energy processes in the cellular system of plants, is responsible for metabolism, strengthens and stimulates the root system to grow, accelerates the onset of flowering and fruiting, helps to increase productivity.

Types of superphosphate

There are two types of superphosphate, which differ in composition, appearance and purpose.

Simple

The agrochemical is sold in the form of gray powder or granules. To obtain finely ground apatite or phosphorite, it is treated with sulfuric acid.Almost all phosphoric acid is well absorbed by the crop.

Compound:

• phosphorus (23–30%);
• calcium (17%);
• sulfur (8–10%);
• magnesium (0.5%);
• nitrogen (6%);
• gypsum and impurities (silica, aluminum and iron phosphates, fluorine compounds).

The advantages of this fertilizer are low price, faster dissolution in the soil (in powder form). Moreover, the product contains almost half of unnecessary impurities: for example, gypsum in simple superphosphate up to 40%.

The product is used in the industrial cultivation of cucumbers, to increase the fertility of compost, green manure and the cultivation of poor soils.

Double

Unlike simple, it contains twice as much phosphorus in the form of calcium monophosphate. Formula: Ca(H2PO4)2*H2O. To obtain phosphorite, it is treated with phosphoric acid, formed from phosphorite or apatite and sulfuric acid.

Mixture composition:

• phosphorus (45–48%);
• nitrogen (15%);
• sulfur (8–10%);
• magnesium (0.5%).

Fertilizer is sold only in granular form. It is more expensive than a simple one, but the price is paid off by a number of advantages: the product is convenient to use, does not contain impurities and does not cake during storage.

It is used as the main fertilizer during the flowering period and fruiting cucumbers, for cultivation of neutral and alkaline soil types. At the same time, on acidic soils, the product is transformed into aluminum and iron phosphates, which are inaccessible to plants.

Granulated

This form of fertilizer is prepared from monophosphate (simple superphosphate). In production, raw materials are slightly moistened, pressed and rolled into granules. The amount of phosphorus reaches 50%, calcium sulfate - up to 30%.

The product dissolves slowly in soil and water, so it lasts longer. The effect after applying superphosphate lasts for several months.

Application:

• main application to the soil for plowing;
• foliar feeding;
• adding at planting;
• for soil cultivation in a greenhouse;
• over large areas.

The fertilizer is poorly fixed in the soil layers, so it is also used on acidic soils, first mixed with chalk.

Ammoniated

A special type of superphosphate for acidic soils. When it is added, the acidity of the soil does not increase, since the reaction is neutralized by ammonia.

Fertilizer composition:

• phosphorus (14–20%);
• calcium sulfate (up to 55%);
• sulfur (12%);
• nitrogen (10%).

Important! Superphosphate of any kind is not mixed with urea, sodium, ammonium and calcium nitrate, or potassium carbonate.

Ammoniated fertilizer gives cucumbers the substances necessary to increase resistance to fungal diseases and stress.

Dosage for cucumbers

Before using fertilizer, be sure to check the acidity of the soil. The granulated agrochemical is applied immediately before watering. Dosages vary depending on the type of fertilizer and type of soil:

1. Dry product is added at the rate of 40–50 g per 1 m2. Double superphosphate is added at 20–30 g per 1 m2. On depleted soils, the dosage is doubled.
2. As a one-time feeding, take 5–10 g per plant.
3. To prepare the working solution, 150 ml of concentrated solution is diluted in a bucket of water.

How to dilute for feeding

To prepare a concentrated solution, take 20 tbsp. l. substances, dissolve them in 3 liters of hot water. The product is stirred periodically until all granules are dissolved. The process takes 12–15 hours.

Timing for fertilizing

Fertilize cucumbers with superphosphate 2-3 times per season:

1. In the fall, when digging up soil and preparing beds for cucumbers.Since the mixture dissolves slowly, it is used no more than once every 2 years.
2. In spring, when sowing or picking seedlings. The substance is added to the holes or rows.
3. Before flowering begins. This fertilizing is important and is responsible for the productivity of the crop. As soon as the first buds appear on the plants, they are fertilized with a superphosphate solution.

Instructions

Depending on the conditions for cultivating cucumbers, some nuances of using nitrogen-phosphorus fertilizers are observed.

In the greenhouse

In order for greenhouse cucumbers to grow healthy and produce a good harvest, they need only 3 feedings with superphosphate:

1. When replacing soil or preparing beds in autumn. Apply 40–50 g of a simple product per 1 m2 or 10–20 g of a double product. The agrochemical is evenly scattered over the ridges and harrowed with a rake, lightly incorporated into the soil.
2. Foliar spraying of cucumbers during budding with a working solution. It is carried out after 14 days.

In protected soil conditions, it is preferable to use double superphosphate. The high content of impurities in simple matter has a toxic effect on plants at high air humidity and a small greenhouse area.

In the open ground

The characteristics of fertilizing in open ground are slightly different from those in greenhouses. On poor soils, the amount of superphosphate is increased. When adding the product during sowing, compost and ash are additionally used so that the young roots come into direct contact with the fertilizer.

Important! If dry necrotic spots of small size appear on the lower leaves of cucumbers, this means that the crop does not have enough phosphorus. Such plants are stunted in growth, shed some of their ovaries and begin to bear fruit later than others.

To add liquid feeding Prepare a working solution in advance and use it only after watering with plain water.

Application during fruiting period

During the flowering period, the bushes are sprayed with a solution prepared from 35 g of superphosphate and 10 liters of water. The product is kept for 24 hours, mixed and filtered to remove any remaining undissolved granules.

Plantings are processed in the morning or evening hours. In the latter case, choose a time before 19:00 so that the cucumber leaves have time to dry before night. Otherwise, wet bushes will appear when exposed to cool temperatures. fungal diseases.

Precautionary measures

Superphosphate belongs to hazard class 3, so gloves are used when working with dry or liquid products. For foliar feeding, choose windless days. While working, it is prohibited to talk, smoke, drink or eat food. After the activities, thoroughly wash your hands, face and other exposed areas of the body with soap.

Attention! Superphosphate is stored at a humidity of no more than 50% and a temperature no higher than +30°C in places inaccessible to children and animals.

If the substance gets into your eyes, rinse them immediately with clean water. If you feel a burning sensation or discomfort after this, consult a doctor.

Reviews

In general, vegetable growers respond positively to the use of such fertilizer for cucumbers. Farmers prefer double superphosphate, note its ease of use and effectiveness, but complain about its poor solubility in water:

Lyudmila, Chelyabinsk: “I have been using double superphosphate for many years. It helps plants set fruit faster, makes roots more powerful, and bushes stronger. I sprinkle dry granules, a little mixed with humus, under the cucumbers, and add the product to the furrows when sowing.The result is that the crop develops better and a rich harvest is guaranteed.”

Konstantin, Rostov-on-Don: “No matter how hard you try, in our time when growing vegetable crops you cannot do without fertilizers, especially if there is nowhere to get organic matter. For example, I live in the suburbs. No one sells humus or manure near me. That's why I buy mineral fertilizers on the market. I choose superphosphate with double phosphorus content. The fertilizer is consumed less and is convenient to use (not powder, but granules). I apply it under cucumbers twice: in the fall, when digging, and before flowering.”

Maria, Stavropol: “I grow cucumbers in a greenhouse. I get a lot of them, and I sell the excess on the market. To increase the quality and quantity of the harvest I use superphosphate fertilizer in the cucumber garden. At first I bought a simple product, but then I read that it contains a lot of impurities and switched to feeding with double phosphorus content. The only negative is poor solubility. I dilute it, as in the instructions, in hot water, but the granules do not completely disappear. And they are slowly consumed in the soil. In the spring, when loosening, I find their remains.”

Conclusion

For the health of cucumbers and high yield, it is important to fertilize them with phosphorus in an easily accessible form. Superphosphate copes well with this task, additionally providing the crop with nitrogen, calcium, sulfur and other useful substances.

When using fertilizer, determine in advance the type and acidity of the soil. Mineral fertilizers are effective only if the instructions are strictly followed.