04/27/2021 2 303 Tubers
Author: Anatoly
During the period of tuber formation and growth, potatoes greatly deplete the soil, so the soil must be fertilized every year. The best time to fertilize potatoes is during planting. But this is not enough for a good harvest; the tubers need to be fed periodically during growth.
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Classification of fertilizers for potatoes
There are many types of fertilizers for potatoes, they differ:
- composition;
- state of aggregation;
- influence on the plant.
Depending on this, each fertilizer is applied to the soil at different stages of potato development.
Main types of fertilizers:
- mineral;
- organic;
- complex.
Greater potato yields are ensured by the use of all types of fertilizers, but with strict adherence to consumption standards. Exceeding the required doses can not only reduce yields, but also destroy plants.
In what cases does it need to be fed?
Potatoes should be fed with urea when characteristic signs appear on the leaves, clearly indicating nitrogen starvation:
- The color of the leaves fades.
- Potato bushes become depressed.
- Noticeable developmental delay.
Within a few days after fertilizing with urea, the condition of the plants returns to normal.
Attention! Urea does not combine well with various herbicides. To prevent negative consequences, carefully read the instructions for the drugs you use.
Mineral fertilizers for potatoes
Mineral fertilizers are produced artificially at chemical plants and contain various micro and macroelements. Some types, for example, ash, can be obtained at home.
Depending on the composition, the following types of mineral supplements differ:
- urea;
- ammonium nitrate;
- nitrophoska;
- ash;
- potash fertilizers;
- nitrogen fertilizers;
- phosphorus fertilizers.
Inorganic fertilizers are more suitable for early potato varieties, which require more nutrition due to the short growing season. Mineral fertilizers quickly enrich the plant, while organic fertilizers do not have time to be fully absorbed.
An additional function of mineral salts is protection against pests and diseases. The weakness of such additives is the possible presence of chlorine in the composition remaining after the production of fertilizers, which has a bad effect on plants.
Urea
Urea is a nitrogen fertilizer, almost 50% of which is nitrogen. It is necessary to apply urea no more than 2 times: in the spring when planting and in the fall after harvesting. It is well suited for alkaline soils, but should not be mixed with superphosphate.
Urea consumption - 1-1.5 kg per 100 sq. m, per hole this is about one small handful. Urea granules should not come into contact with planting material. You need to put fertilizer in the hole, cover it with soil and then put in the potatoes. You can also dissolve them in water (30–40 g per 10 liters of water) and water the holes with the resulting solution before planting.
If no fertilizers were applied during planting, you can water the potato rows with a urea solution during the flowering period, when the tubers are actively growing. In this case, it is necessary to avoid getting the solution on the leaves to prevent the formation of burns.
Ammonium nitrate
Ammonium nitrate contains about 35% nitrogen, so it is used in small quantities. One bush will require 10–20 g of product, depending on the level of soil depletion. When used correctly, saltpeter can be used annually.
The drug can be applied both in granular and dissolved form. When planting, dry saltpeter is usually added to the hole, sprinkled with a small amount of soil so that the tubers do not come into contact with the granules. A solution of nitrate (20 g per 10 liters of water) is most often used for feeding during the growth period of the green part of the vegetable, i.e. before flowering.
Nitrophoska
Nitrophoska is a source of:
- nitrogen (11%);
- phosphorus (10%);
- potassium (11%).
The percentage of elements may differ in preparations for different purposes. Rapid absorption of elements is ensured by the fact that beneficial substances are in the form of salts.
Nitrophoska is added during planting at the rate of 1 tbsp. spoon for one bush. It is possible to apply fertilizer for potato planting in the fall, which will greatly save time in the spring, especially on large areas. In this case, no more than 80 g per hectare of land is used.
Ash
Ash is formed as a result of burning plant waste and contains more than 70 different useful substances, so it is very necessary for potatoes. But you don’t need to use it thoughtlessly; you need to know what material it is made of, since its composition depends on this.
The content of main elements in ash of different origins:
- from wood - up to 15% potassium, 7% phosphorus;
- from sunflower and buckwheat - potassium and 35% calcium;
- from grain waste (for example, wheat) - most phosphorus;
- from potato tops - 30% potassium, 20% calcium and up to 10% phosphorus.
The composition of the ash is completely free of nitrogen, so nitrogen-containing additives are used along with it. But these fertilizers cannot be mixed.
Ash consumption when planting potatoes: 5–10 kg per hundred square meters, which is about 200 g per hole. For acidic soils, consumption can be increased to 20 kg per square meter. m, since in addition to feeding plants, ash performs the function of neutralizing soil acidity. You can fertilize the ground with ash several times: both in autumn and in spring.
Potash fertilizers
Potassium fertilizers are very necessary for the growth of roots and tubers; in addition, they protect potatoes from fungal diseases. Most often, such fertilizers contain a large amount of ash with the addition of phosphorus, calcium and other trace elements.
On average, you will need about 15 kg of fertilizers per hundred square meters of land. For sandy soil, this standard can be slightly increased, and for clayey soil, reduced. The time of application is the beginning of tuber formation. You can pre-fertilize the soil in the fall after plowing.
Nitrogen fertilizers
Plant growth depends on the amount of nitrogen in the soil, so nitrogen fertilizers are an integral part of spring feeding of plants. But it is not recommended to exceed the permissible dose, otherwise only the green part of the potato will grow.
Nitrogen fertilizers come in liquid and granular form, and beneficial substances are found in the form of various compounds that are easily absorbed.
The disadvantage of nitrogen additives is that they increase the acidity of the soil, so it is recommended to use chalk, lime or dolomite together with them. Currently, ready-made mixtures of nitrogen fertilizers with all the necessary substances and in the required proportions are available for sale.
Phosphorus fertilizers
Phosphorus fertilizing has a good effect on the resistance of plants to frost and the quality of tubers. Phosphorus must be added along with planting potatoes.
Separately, phosphorus is sold in the form of phosphates with a phosphorus content of 20 to 50%. When choosing a dose, it is necessary to take into account that phosphorus components are also found in other fertilizers, such as ash, manure, humus, as well as in complex mineral additives.
Read more about mineral fertilizers and the timing of their application, taking into account the type of soil, in the video filmed by the Gardener Newspaper channel.
Organic fertilizers
Organic fertilizers are natural additives of plant or animal origin that are very well absorbed by crops. The composition of organic matter depends on the components and method of formation, but in any case it has a beneficial effect on the chemical composition of the earth.
Types of organic fertilizers:
- humus;
- chicken droppings;
- manure;
- compost;
- slurry.
Organic fertilizers contain a large amount of nitrogen, which is necessary only during the period of potato growth. Therefore, organic matter is added either in the spring during planting, or before winter after harvesting.
The disadvantage of organic fertilizers, especially fresh manure, is the possible contamination of the soil by pests that live in the waste.
Humus
Humus is pure rotted manure or with the addition of compost. It will take about 2 years to obtain humus. But this is a very useful and safe fertilizer. It can be added to the hole or applied in the fall before plowing. Humus loosens the soil well and can be used as mulch.
Depending on the nutritional value of the soil, the humus consumption is 150–250 g per hole. In the fall, humus must be embedded in the ground so that it does not dry out.
Chicken droppings
Chicken manure is very effective for the growth of various crops, including potatoes, due to the high concentration of useful elements. It should absolutely not be used fresh and very carefully when used dry.
Before use, chicken manure is diluted in water (1 liter of manure per 15 liters of water) and infused for several days in a warm place or in the sun. For one bush you can use 1-1.5 liters of the prepared solution.
Chicken manure can be added in diluted or dry form in the spring, and fresh in the fall for digging. In winter, litter consumption is about 15 kg per hectare of land. In spring, no more than 20 g of dry raw materials are added to the hole.
Manure
Manure contains a large amount of nitrogen and many different microelements. The composition of manure depends on the type of animal from which it is obtained and the diet of that animal. The most nutritious are horse and cow manure. But in its fresh form it can only be used in the fall before plowing or digging the ground. During the winter, the manure rots and enriches the soil with useful substances. It is applied at the rate of 400 kg per square meter. m.
In spring, manure can only be fertilized in the form of slurry, which you can prepare yourself.
It is not recommended to use manure more than once every 3-5 years. Annual application of manure will reduce crop yields.
Compost
Compost is obtained by rotting plant and food waste. Like humus, compost is formed after 1-2 years and is a cheap, natural and useful fertilizer.
Compost is added to the holes in the spring along with potatoes; its consumption is about 1 liter per bush.
Slurry
Slurry is an infusion of fresh manure, which is obtained after fermentation of a composition made in the proportions: 1 part raw material and 9 parts water. The slurry is used in the spring when planting or during the initial period of vegetable growth; a liter of infusion is enough for one bush.
Humus
Manure
Compost
Diluted chicken manure
Scheme of foliar feeding
Foliar feeding helps the plant to develop normally, in addition, it prevents many fungal diseases.
For example, nitrogen sprays will protect potatoes from nematodes. Treatments with nettle infusion are effective against aphids. Late blight will be prevented by treatment with copper sulfate. To prevent voids from forming in the tubers, treatment with boron is necessary .
Manganese will improve the taste and increase the sugar content of the product, and spraying with copper sulfate a month before harvest will increase the shelf life of tubers, and weight loss during storage will be reduced to a minimum. Boron-manganese treatment is carried out in the tuber formation phase, after flowering. During the growth period of the tops, the best fertilizer will be urea spraying. The last treatment on the leaf will be phosphorus. It is carried out twenty days before digging up root crops. Humates are used throughout the growing season, and potassium is applied per leaf during the period of tuber growth, after flowering.
Why do you need boron for potatoes?
Complex fertilizer
Complex fertilizers consist of 2-3 main elements with a small amount of various microelements. What main substances are contained in the bait is indicated by its name. The roots “nitro” and “ammo” indicate the presence of nitrogen, “phos” - phosphorus, “ka” - potassium. Fertilizers with all three elements are more effective.
The following types of complex fertilizers are widely used:
- ammophos;
- ammophoska;
- nitroammophoska;
- Diammophoska.
There are also special complexes for certain types of crops, including potatoes.
Ammophos
Ammophos is a balanced complex of nitrogen and phosphorus in amounts of 12 and 52%, respectively. Despite the fact that nitrogen is present in the composition, ammophos is considered a phosphorus fertilizer. Well suited for arid areas, often used in conjunction with ammonium nitrate.
For growing potatoes, it is preferable to use ammophos rather than phosphates or superphosphates.
It is used for growing potatoes both as the main fertilizer (in the fall 15–25 g per square meter, in the spring 2 g per hole), and as an additional fertilizing during the growth of the vegetable (5–10 g per meter of row spacing with mandatory mixing with soil).
Ammofoska
Ammophoska contains three main components:
- 12% nitrogen;
- 15% phosphorus;
- 15% potassium with the addition of 14% sulfur.
Sulfur promotes nitrogen absorption and prevents soil acidification.
Ammophoska is a nitrogen-phosphorus additive necessary during plant growth. For 1 sq. m, 20–30 g of the drug is used.
Nitroammofoska
Nitroammofoska, unlike ammophoska, is a more effective remedy. This is due to the fact that the beneficial substances in it are presented in the form of various compounds that are easily absorbed by the culture.
There are several types of nitroammophoska, which differ in the percentage of elements:
- nitrogen;
- phosphorus;
- potassium
For potatoes, fertilizer with an equal amount of substances is more suitable. If there is a lack of phosphorus and potassium, nitroammophoska with a high content of these elements is used; there is also a drug with a high nitrogen content.
To apply in the spring, you will need 40 g of fertilizer per square meter. m of land. 1 teaspoon of the drug is added to the well. You can feed plants with a solution of nitroammophoska.
Diammofoska
Diammofoska refers to a concentrated complex preparation with a high content of phosphorus and potassium.
Its composition:
- 10% nitrogen;
- 26% phosphorus;
- 26% potassium.
Diammofoska is used on depleted soils and has a good effect on potato yields and tuber quality.
If digging is done in the spring, fertilizer is applied in bulk before the loosening procedure: 20 g per square meter. m. 5 g of the drug is added to the well.
Ammophos
Nitroammofoska
Diammofoska
Ammofoska
The importance of foliar feeding
A feature of potatoes is their poor susceptibility to fertilizers with high demands on nutrients. To carry out root nutrition, gardeners have to supply a large amount of fertilizer, which is sometimes simply unprofitable, given the monetary costs of organic and industrial fertilizers. Feed feeding by leaf is often a more effective and cost-effective way to manage potatoes. But foliar feeding of potatoes also has its own characteristics.
Adjuvants
The specific structure of the potato leaf is such that if it is not sprayed correctly, the nutrients will be poorly absorbed.
The epidermis of potato leaves is multilayered, covered on top with a protective natural film of wax and cutin. This barrier reduces the effectiveness of foliar feeding by three times. To overcome this protective layer, special agents under the abbreviation surfactants are used as part of leaf dressings - surfactants. The second name is adjuvants. These substances increase the area of liquid spreading over the surface of the sheet . At the same time, adjuvants retain nutrients and damage the dense protective layer. Through microdamage, nutrition enters the plant.
Often, ready-made formulations for processing potatoes already contain surfactants. Before purchasing fertilizer, carefully read the composition. If adjuvants are not available, you will have to buy them separately and add them for spraying.
Calculation of the amount of fertilizers
When calculating the required amount of fertilizer, you need to focus on the required soil composition for potatoes and the fertility of the land. In addition, many supplements contain several elements, and when compiling a nutritional mixture, the total amount of the substance in all preparations must be taken into account. This will help to avoid an overdose of soil, this is especially important in relation to nitrates.
It is important to know that fertilizers with a large amount of nitrogen can only be applied during the growth period of greenery. After flowering, tubers begin to form, and excess nitrogen will stop their growth and continue to develop tops. The result will be beautiful lush greenery, but a small and meager harvest. Phosphorus and potassium are needed for tuber development.
On average, for the entire period of potato crop growth per 1 sq. m will need:
- 20 g nitrogen;
- 40–45 g potassium;
- 10 g phosphorus;
- 5–6 g magnesium;
- other elements in smaller quantities.
But it is not recommended to add everything at once in such quantities.
For a good potato harvest, there are several proven mixtures of organic and inorganic fertilizers (calculation per 1 sq. m):
- 1 bucket of humus, 1 tbsp. ash, 3 tbsp. spoons of nitrophoska;
- 10 kg of humus, 20 g of ammonium nitrate, 20 g of potassium sulfate, 30 g of superphosphate, 450 g of dolomite flour or lime;
- 20 g of ammonium nitrate and 20 g of potassium sulfate.
In the absence of organic matter, complex fertilizers such as nitrophoska or nitroammophoska are applied.
Severely depleted soil must be fertilized with a more concentrated mixture, and for fertile soil, the amount of ingredients must be reduced.
Why fertilize potatoes?
Potatoes, like tomatoes, are vegetables of the same family, Solanaceae. In science, the crop is called tuberous nightshade (Solanum tuberosum) - a herbaceous tuberous perennial.
Reference. We owe the appearance of “earth apples” in Russia to Peter I. The Russian Tsar brought a bag of tubers from Holland at the end of the 17th century. Gradually, by the mid-19th century, the root vegetable literally became the second bread.
Due to the “kinship”, the requirements of potatoes for basic nutrition and seasonal feeding are very similar to those for fertilizing tomato seedlings. But still, some features of growing, planting and care exist.
Let us dwell in more detail on the important factors and features of seasonal fertilizing that directly affect the full ripening of a high-quality and rich harvest.
Factors affecting yield
Let us highlight the mandatory procedures that directly affect high potato yields:
- pre-sowing soil nutrition with nitrogen, phosphorus and potassium (autumn or spring);
- preparation of planting material (processing of tubers before planting);
- nutritional mineral supplements before and after potato flowering;
- pre-harvest desiccation (drying of tops);
- preventive feeding (adding a complex of microelements and fungicides).
