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Phosphorus is essential for all plants, including tomatoes. It allows you to absorb water, nutrients from the soil, synthesize them and transfer them from the root to the leaves and fruits. Providing normal nutrition for tomatoes, the microelement makes them strong, resistant to bad weather and pests. There are many phosphate fertilizers for feeding tomatoes. They are used at all stages of growing crops. For example, adding superphosphate to the soil and top dressing of tomatoes allows you to get a good harvest without problems and hassle. You can find out in detail about when and how to use superphosphate fertilizer for tomatoes below in the article.
Types of superphosphate
Among all phosphorus-containing fertilizers, superphosphate occupies a leading position. It is he who is more often used by gardeners to feed various vegetable and berry crops. However, superphosphate is also different. Arriving at the store, you can see simple and double superphosphate. These fertilizers differ in their composition, purpose, method of application:
- Simple superphosphate contains about 20% of the main trace element, as well as a certain amount of sulfur, magnesium and calcium. Manufacturers offer this fertilizer in powder and granular form. It is perfect for soil of any nutritional value. Tomatoes are always responsive to feeding with simple superphosphate. It can be used during autumn or spring digging of the soil, for introduction into the hole during planting seedlings, for root and foliar feeding of tomatoes.
- Double superphosphate is a highly concentrated fertilizer. It contains about 45% easily digestible phosphorus. In addition to the main trace element, it contains magnesium, calcium, iron and some other substances. It is used at the stage of soil preparation for growing tomatoes, as well as for feeding tomatoes by watering at the root no more than 2 times during the entire growing season. The substance can replace simple superphosphate when the concentration of the solution is halved.
Simple and double superphosphate can be found in powdered and granular form. Substances can be used in dry form for embedding into the soil or in the form of an aqueous solution, an extract for watering and spraying tomatoes. It is recommended to introduce double superphosphate into the soil in the fall in order for it to spread throughout the mass of the soil, thereby reducing the concentration of the main substance.
On sale you can find ammoniated, magnesian, boric and molybdenum superphosphate. These types of fertilizers, in addition to the main substance, contain additional ones – sulfur, potassium, magnesium, boron, molybdenum. They can also be used to feed tomatoes at various growing stages. Thus, ammoniated superphosphate is recommended to be applied to the soil when planting seedlings for better rooting of plants.
The introduction of a microelement into the soil
For growing seedlings of tomatoes, the soil can be prepared by mixing sand, soddy soil and peat. The resulting mixture must be disinfected and filled with nutrients. So, to obtain a good, nutritious substrate, it is necessary to add 3 part of soddy soil and 1 parts of sand to 2 parts of peat. Additionally, you can add sawdust treated with boiling water in the amount of 1 part.
Fertilizers must be added to the soil for growing seedlings. 12 g of simple superphosphate, 90 g of dolomite flour, 300 g of potassium sulfate and 40 g of urea should be added to 30 kg of substrate. The resulting microelement mixture will contain all the necessary substances for the successful growth of strong seedlings.
The soil in which tomato seedlings are to be planted must also be filled with minerals. During autumn digging into the soil for every 1 m2 it is necessary to add 50-60 g of simple superphosphate or 30 g of double fertilizer. Substances should be applied directly to the hole before planting seedlings at the rate of 15 g per 1 plant.
It is worth noting that sprinkling superphosphate on top of the soil is not effective, since tomatoes can only absorb it when wet at the depth of the roots or when spraying liquid fertilizer on the leaves of the plant. That is why, when applying fertilizer, it is necessary to bury it in the soil or prepare an extract from it, an aqueous solution.
Seed dressing
The first feeding of tomatoes with a fertilizer containing phosphorus must be carried out 15 days after the dive of young plants. Previously, it was recommended to use only nitrogen-containing substances. The second feeding of seedlings with phosphorus should be performed 2 weeks from the day of the previous fertilization.
For the first feeding, you can use nitrophoska, which will contain the required amount of potassium, phosphorus and nitrogen. This fertilizer is diluted in water based on the ratio: 1 tablespoon of the substance per 1 liter of water. This volume of liquid is sufficient for watering 35-40 plants.
You can prepare a top dressing similar in composition to nitrophoska by mixing 3 tablespoons of superphosphate with 2 tablespoons of potassium sulfate and the same amount of ammonium nitrate. Such a complex will contain the necessary substances for the growth and development of tomato seedlings. Before making all of these components must be dissolved in water with a volume of 10 liters.
Also, for the first feeding of tomato seedlings, you can use Foskamide in combination with superphosphate. In this case, to obtain fertilizer, it is necessary to add substances in the amount of 30 and 15 g, respectively, to a bucket of water.
For the second feeding of tomato seedlings, the following phosphate fertilizers can be used:
- if the seedlings look healthy, have a strong trunk and well-developed foliage, then the drug “Effekton O” is suitable;
- with a lack of green mass, it is recommended to feed the plant with “Athlete”;
- if the tomato seedlings have a thin, weak stem, then it is necessary to feed the tomatoes with superphosphate, prepared by dissolving 1 tablespoon of the substance in 3 liters of water.
After carrying out two mandatory dressings, tomato seedlings are fertilized as needed. In this case, you can use not only root, but also foliar top dressing. Phosphorus is perfectly absorbed through the surface of the leaf, so after spraying tomatoes with a solution of superphosphate or other phosphate fertilizer, the effect will come in a few days. You can prepare a spray solution by adding 1 tablespoon of the substance to 1 liter of hot water. This solution is highly concentrated. It is insisted for a day, after which it is diluted in a bucket of water and used to spray seedlings.
A week before the proposed planting of plants in the ground, it is necessary to conduct another root dressing of seedlings with fertilizer prepared from superphosphate and potassium sulfate. To do this, add 1,5 and 3 tablespoons of each substance, respectively, to a bucket of water.
In the preparation of dressings, its amount should be halved.
Thus, phosphorus is essential for tomatoes at the seedling growing stage. It can be obtained by using ready-made complex preparations or by adding superphosphate to a mixture of minerals. Also, superphosphate can be used as the main and only component for the preparation of root and foliar dressings.
Feeding tomatoes after planting
Feeding tomato seedlings with phosphorus is aimed at developing the root system of the plant. Seedlings do not absorb this trace element well, so it is necessary to use superphosphate in the form of an extract or solution. Adult tomatoes are able to absorb simple and double superphosphate well. Plants use 95% of phosphorus to form fruits, which is why superphosphate should be actively used during flowering and fruiting.
10-14 days after planting tomatoes in the ground, you can feed them. To do this, use a complex fertilizer containing nitrogen, potassium and phosphorus or organic matter with the addition of superphosphate. So, mullein infusion is often used: add 2 g of cow manure to 500 liters of water, then insist the solution for 2-3 days. Before use for tomatoes, dilute mullein with water 1: 5 and add 50 g of superphosphate. Such top dressing for a tomato will contain the whole range of essential minerals. You can use it 2-3 times during the entire growing period.
How to determine the lack of phosphorus
To feed tomatoes, organic fertilizers with the addition of superphosphate or complex mineral fertilizers containing phosphorus are more often used. The frequency of their application depends on the fertility of the soil and the condition of the plants. As a rule, 2-3 top dressings are used on soils of medium nutritional value, 3-5 top dressings may be needed on poor soils. However, sometimes tomatoes receiving a micronutrient complex show symptoms of a lack of phosphorus. In this case, it is recommended to use superphosphate fertilizer extraordinary.
In tomatoes, signs of a lack of phosphorus are:
- leaf color change. They become dark green, sometimes turning purple. Also a characteristic sign of a lack of phosphorus is the twisting of the leaves inward;
- the stem of the tomato becomes brittle, fragile. Its color becomes violet as phosphorus starvation progresses;
- the roots of tomatoes wither, stop consuming nutrients from the soil, as a result of which the plants die.
You can see the lack of phosphorus in tomatoes and hear the comments of an experienced specialist in solving the problem in the video:
When observing such symptoms, tomatoes must be fed with superphosphate. For this, a concentrate is prepared: for 1 liter of boiling water, a glass of fertilizer. Leave the solution for 8-10 hours, then dilute it with 10 liters of water and pour 500 ml of tomatoes under the root for each plant. For root dressing, superphosphate extract prepared according to the classic recipe is also excellent.
Phosphorus deficiency can also be compensated by foliar feeding: a spoonful of superphosphate per 1 liter of water. After dissolution, dilute the concentrate in 10 liters of water and use for spraying.
Extract from superphosphate
Superphosphate for feeding tomatoes can be used in the form of an extract. This fertilizer has an easily accessible form and is quickly absorbed by tomatoes. You can prepare the hood using the following technology:
- add 3 mg of superphosphate to 400 liters of boiling water;
- put the liquid in a warm place and stir occasionally until the substance is completely dissolved;
- leave the solution for a day, after which it will look like milk, which means that the extract is ready for use.
Instructions for use of the extract recommend diluting the finished concentrated solution with water: 10 mg of the extract per 150 liters of water. You can make the fertilizer complex by adding 1 tablespoon of ammonium nitrate and a glass of wood ash to the resulting solution.
Other phosphate fertilizers
Superphosphate is an independent fertilizer that can be purchased at specialized stores and used as a top dressing for tomatoes. However, farmers are also offered other fertilizers with a high content of phosphorus:
- Ammophos is a complex of nitrogen (12%) and phosphorus (51%). The fertilizer is water soluble and easily absorbed by tomatoes.
- Nitroammophos contains an equal amount of nitrogen and phosphorus (23%). It is necessary to use fertilizer with slow growth of tomatoes;
- Nitroammophoska contains a complex of nitrogen with potassium and phosphorus. There are two brands of this fertilizer. Grade A contains potassium and phosphorus in the amount of 17%, grade B in the amount of 19%. Using nitroammophoska is quite simple, since the fertilizer is easily soluble in water.
It is necessary to use these and other phosphate substances in accordance with the instructions for use, since an increase in dosage can lead to an excessive content of the trace element in the soil. Phosphorus overload symptoms are:
- accelerated growth of stems without enough leaves;
- rapid aging of the plant;
- edges of tomato leaves turn yellow or brown. Dry spots appear on them. Over time, the leaves of such plants fall off;
- tomatoes become especially demanding on water and, at the slightest deficiency, begin to actively fade.
To summarize
Phosphorus is very important for tomatoes at all stages of cultivation. It allows the plant to develop harmoniously and correctly, consuming other microelements and water from the soil in sufficient quantities. The substance allows you to increase the yield of tomatoes and make the taste of vegetables better. Phosphorus is especially necessary for tomatoes during flowering and fruiting, because each 1 kg of ripe vegetables will contain 250-270 mg of this substance, and after eating such products will become a source of useful phosphorus for the human body.