For proper development, every plant needs important nutrients. One of them is potassium. If there is a deficiency, garden, vegetable and ornamental crops should be fed. We will tell you when and how to apply potash fertilizers.
Any crop needs potassium more than any other nutrient. In plants, potassium mainly accumulates in the cytoplasm and cell sap. There is less of it in roots, seeds, tubers and any old parts of plants than in young leaves and stems.
Thanks to this substance, the metabolism of proteins and carbohydrates in cells improves, sugar accumulates, photosynthesis accelerates, the plant tolerates drought better, and adapts to low temperatures and pathogenic organisms. Potassium is especially important for flowering plants, since when it is deficient, the buds either do not set at all, or the flowers grow very small.
This is what plants that lack potassium look like
The importance of potassium fertilizer is difficult to overestimate. If there is not enough potassium in the soil, then the flowers and fruits of the plant do not form. Therefore, you can be left without a harvest. This element is indispensable for the development and growth of sunflower, buckwheat and various vegetables, in particular beets and potatoes. But grain crops are less sensitive to potassium deficiency.
Why do cucumbers need potassium nitrate?
Potassium nitrate is a universal fertilizer that is used on almost any soil. The trace element is contained here in a form accessible to cucumbers; there are no unnecessary impurities. Fertilizing with potassium nitrate will make cucumbers resistant to adverse factors, especially drought: the product stimulates easier absorption of soil moisture.
Regular application of the agrochemical balances the processes of photosynthesis and respiration, strengthens the root system of plants, accelerates the development and growth of green mass.
What is useful during the fruiting period?
The fertilizer contains the optimal ratio of nitrogen and potassium to obtain quality parameters for fruits:
- cucumbers do not crack;
- Fewer barren flowers are formed;
- productivity increases;
- vegetables are smooth and beautiful;
- taste improves.
Benefits of potassium sulfate for tomatoes
Feeding tomatoes with potassium sulfate (chemical formula K2SO4) comes first, along with the need to saturate this vegetable crop with substances such as nitrogen and phosphorus.
Potassium sulfate as a fertilizer has a crystalline structure and easily dissolves in water; in appearance it resembles washing powder.
Potassium sulfate as a fertilizer is necessary for tomatoes at all vegetative stages of their development, starting from the appearance of the first leaves and transplanting seedlings into open ground and ending with the formation of ovaries and the fruiting period.
The benefits of potassium sulfate as a fertilizer for tomatoes are as follows:
- stimulating the growth of green mass and shoots;
- ensuring better rooting of the plant after transplanting it into open ground;
- positive effect on the taste of the resulting crop. In the absence of feeding with this substance, the taste of the tomatoes will become somewhat sour, and they will clearly need additional sugar;
- positive effect on the speed of crop ripening;
- increasing the general immunity of the plant, enhancing its resistance to various types of pests and diseases;
- stimulation of general processes of adaptation to the influence of various natural and weather factors.
Important!
Despite the invaluable benefits that potassium sulfate provides as a fertilizer for tomatoes, it is necessary to strictly observe the dosage and frequency of its application as a fertilizer for tomatoes. An excess of this substance is just as harmful to representatives of the Solanaceae family as its deficiency. The main signs by which one can judge an excess of fertilizer are:
- thinning of tomato leaves and the entire green mass of the plant as a whole;
- death of the upper shoots;
- the lower leaves have a wrinkled structure and are covered with dark spots;
- The roots of the plant weaken and lose the ability to grow into the ground.
Composition and properties of fertilizer
Potassium nitrate, potassium nitrate or potassium nitrate (mixture formula: KNO3) is a potassium-nitrogen agrochemical produced chemically. It is a white, odorless, crystalline powder or granules.
The mixture contains 2 active ingredients:
- nitrogen - 13%;
- potassium - 46%.
Nitrogen helps cucumbers grow faster and form green mass.
The main advantages of potassium nitrate over other fertilizers with the same microelement:
- does not contain chlorine, which is important for chlorophobic cucumbers;
- dissolves well in water;
- low toxic.
Potassium nitrate is flammable and explosive, so store it in a cool, dry place, away from sources of heat and fire. For the same reasons, fertilizer is not mixed with organic matter.
Important! In the room where the agrochemical is contained, maintain humidity at 60–65% so that the product does not harden.
Signs of potassium deficiency and excess in plants
If a plant lacks potassium, ammonia begins to accumulate in its cells. This leads to instability to fungal diseases and the death of shoots. After all, the formation of protein and the synthesis of complex carbohydrates stops in plant cells.
However, excess potassium also negatively affects plant development. Therefore, unlike phosphate fertilizers, you need to be careful with potash fertilizers and not exceed the dosage.
Potassium deficiency mainly affects crops growing on light peat soils, since this element is better preserved in heavy clay soil.
Symptoms of potassium deficiency
With a deficiency of this element, cucumber leaves become smaller in size, become pale, turn yellow, become covered with brown spots, similar to burns, along the edges and die. The stronger the crop's need for potassium, the more spots on the plants.
The lack of the element manifests itself on the lower leaves, since potassium is quite mobile and, with a limited supply, moves to the young parts of the bushes. In hot weather, the manifestation of nutritional deficiency increases. Such cucumbers feel the need for water earlier than others and wither.
Potassium deficiency has the greatest impact on the quantity and quality of the crop. Flowering is accompanied by an abundance of barren flowers and partial death of the ovaries. The fruits grow small, uneven in diameter, and twisted.
Options to choose from
Fertilizers, including phosphorus and potassium, are the widest group of one-, two- and multi-component fertilizers that are intended for use at various stages of plant development. Thus, preparations that include additional nitrogen (“Nitroammofoska”, “Azofoska”, “Nitrophoska”, etc.) are used mainly in the spring, when it is necessary to quickly increase green mass.
In summer, phosphorus fertilizers for tomatoes should include exclusively two main minerals. It is also useful if the composition contains various microelements (iron, boron, copper, magnesium, calcium, zinc, molybdenum, etc.), which help to form the appropriate taste and aroma of the fruit, but the presence of nitrogen is completely undesirable, since it provokes fattening of sterile shoots , which negatively affects the harvest.
In general, drugs in the “phosphorus-potassium” category are divided into three groups:
- Water soluble - suitable for all types of soil and growing methods, used everywhere as root dressings and for foliar spraying. These include: simple or double superphosphate, potassium sulfide, superphosphate, potassium monophosphate, etc.
- Hardly soluble - most often applied in dry form, they are most relevant during the autumn digging period, since they have a prolonged effect. This includes: phosphorous flour, vivianite, ammophos, diammophos, etc.
- Slightly soluble in water, but good in the presence of acid - as universal preparations they are excellent for all vegetable crops (including tomatoes) growing in soils with high acidity. This group includes: thermophosphate, precipitate, bone meal, etc.
How to prepare the solution correctly
The dissolved substance replenishes the nutritional balance much faster. Fertilizer in liquid form is used for visible signs of potassium deficiency in the form of foliar feeding.
For the procedure to be beneficial, it is important to know the exact dosage when preparing the working fluid and follow the instructions on the pack of agrochemicals.
Proportions and instructions
Basic dosages of the substance:
- For foliar feeding, more concentrated solutions are used: 25–30 g of mixture per 10 liters of water. The solution is consumed on the day of preparation.
- When watering at the root, the dosage is reduced to 15–20 g/10 l.
- For application to the soil in dry form (dry fertilizing, autumn digging of soil on the site and in the greenhouse, preparation of soil mixture for seedlings), use 15–20 g/m2.
It is better to use powder fertilizer for preparing liquid fertilizer, and granules are best applied to the soil in dry form. Granulated potassium nitrate is saturated with moisture more slowly and is stored longer.
Potassium feeding of cucumbers: when and why to do it
Organic for lovers of organic vegetables
Bird droppings or manure, wood ash, and nettle infusion are used as natural fertilizers. Mullein is used to make compost for feeding bushes. Dig a hole where plants, manure, soil, and food waste are placed. Compost takes about 9 months to rot. If it is not possible to make a compost pit, you can spread manure over the area in the fall and dig it up.
The most popular folk recipes are:
- nettle infusion. Mow the nettles until the seeds form. Cut the stems, place them in a large container, add crackers, yeast and stale bread. The mixture should fill the container ¾ full. Add water, but not to the very edge, because the solution will still ferment. After 5 days, the concentrate is ready - filter it, dilute it with water 1:10, water the cucumbers once every 7 days;
- herbal infusion. Chamomile, wormwood, tomato shoots, yarrow are cut and the container is filled 1/8 full. Add 10 liters of water, 1 tsp. humate. After 5 days, filter, add wood ash and use for root feeding. Field bindweed should not be used for infusion - it releases toxins. Cereals, which produce alcohol during fermentation, are also not suitable.
Potassium nitrate for cucumbers during fruiting period
During the flowering period, future cucumbers are laid. How many there will be and how they will grow depends on the chosen variety, the efforts of the gardener and good nutrition. How to feed vegetables at this stage of the growing season? Potash fertilizers are applied both at the root and by spraying the plants, depending on the type of soil in the garden and the health of the crop.
Root feeding
Used on light soil types as it gives quick results:
- To speed up flowering, cucumbers are fertilized in the phase of 2-3 true leaves. The dose for preparing the solution is 2-3 tbsp. l. (15–20 g) per 10 liters of water.
- When the first flowers appear, 20 g of potassium nitrate and 30 g of superphosphate are dissolved in 10 liters of water. This product is used to feed the plants after watering. This amount of liquid is enough for 15 bushes.
- At the moment of growth of the main mass of fruits, fertilizing is repeated (two weeks after the second fertilization).
Each subsequent feeding begins at the appropriate time: wait at least two weeks between procedures.
Attention! If cucumbers are regularly fed with potassium nitrate, then root watering will be sufficient.
Greenhouse vegetables require nutritional supplementation with potassium more often than those grown in open ground. The reasons for this are simple: the necessary elements do not fall with rain, watering washes them away from a limited area, and a closed space increases the risk of fungal diseases. If in the open ground, with cucumbers in good condition, only fertilizing is left during the fruiting period, then all 4 are carried out in the greenhouse.
Foliar feeding
On heavy and clayey soils, spraying with a solution of nitrate will be more effective. The same method is used if visible signs of potassium starvation are noticed on the plants. For spraying, granules or powder are dissolved in water. To avoid burning the leaves, prepare a less concentrated solution: 1-2 tbsp. l./10 l of water.
Rules for processing plants:
- spray in the morning and evening hours;
- fertilize only in dry, windless and cloudy weather;
- use personal protective equipment (gloves, goggles), and after work, wash your face and hands thoroughly with soap.
Leaves are treated no more than 2-3 times during the entire growing season.
The benefits of potassium fertilizers for cucumbers
Compositions with potassium improve the characteristics of the plant and the taste of the fruit:
- Fertilizer improves immunity, protects against pest attacks, and reduces the likelihood of contracting infections.
- Normalizes metabolic processes in the plant, resulting in increased resistance to drought and frost.
- Promotes active flowering and full fruit formation.
- The shelf life of the harvested crop is increasing.
In order for the plant to develop successfully, the component must be sufficient for the entire growing season.
Advice from experienced summer residents
Many farmers have appreciated the benefits of fertilizer for cucumbers.
Oleg, Kostroma region: “I grow cucumbers in a greenhouse for sale, so the friendly return of the harvest is of great importance. At first I fed the cucumbers with potassium chloride at the time of fruit set, but in 2022 I decided to try potassium nitrate from. I liked that the fertilizer is already in liquid form. Preparing the solution is a pleasure: you measure out a cap onto a bucket of water, and that’s it! The price of the fertilizer is higher than that of cheap analogues, but in my case the investment was justified.”
Olga, Moscow region: “I have acidic soil in my garden. The fertilizer for cucumbers is good, but if you look from the point of view of agrochemistry (I am a chemist by training), then only one element is used - potassium. Nitrogen does not work on acidic soils, but on purely alkaline soils, on the contrary, potassium will lie as a dead weight. For me, a pensioner, it is also expensive. I feed my cucumbers with ash and am happy with the result.”
Anastasia, Klin: “My husband and I are just starting to garden. The plot was given with poor soils. In the fall, manure was applied, and in the spring, cucumbers were planted under the film. The culture was growing and had already begun to bear its first fruits. We were about to harvest this weekend when we discovered that the lower leaves had turned yellow. Whatever we did: watered, looked for pests, used home remedies, but the plants stopped growing and setting fruit. A neighbor helped, advising us to spray them with potassium nitrate. I did everything as in the instructions. After 4-5 days, the cucumbers came to life and continued to set ovaries.”
Effective products of the agrochemical complex
When choosing potassium fertilizer for cucumbers in the greenhouse and in the garden, you can safely use products from the agrochemical industry. Potassium sulfate and potassium nitrate work well. The latter contains nitrogen, so it is advisable to use it in the spring to grow greenery.
Monopotassium phosphate is stirred in a bucket of water in the amount of 15 g. This volume is enough to water 3-5 bushes. An excess is harmful, so you need to dose exactly according to the instructions.
Calimagnesia contains 30% potassium, 10% sulfur, 17% magnesium and 3% chlorine. Because of the last component, it is used in the fall, for digging. Dosage - 20 g per 1 sq. m. Until spring, the chlorine will have time to evaporate.
Getting a good harvest is not difficult if you follow the advice of experienced farmers and apply fertilizers at the right time in the exact dosage.
The role of potassium in the growth and development of crops
Potassium, along with nitrogen and phosphorus, is the most important element that ensures the active life of the plant. It promotes the normal course of photosynthesis, controls the migration of carbon, which is the building material of the cell, from leaves to other organs (to fruits, for example), with sufficient quantity, it can increase the plant’s resistance to frost and sudden temperature changes, and also allows the plant to better tolerate drought.
Potassium increases resistance to the negative influence of pathogens of various diseases, as well as pests. This is especially true when weather conditions are such that the pest population increases.
Important! Ideally, potassium should be supplied to cucumbers without chlorine, which can interfere with the absorption of both potassium and nitrogen, and in large doses inhibit the development of cucumbers, which directly affects the quality and quantity of the crop.
When to add potassium to cucumbers
Fertilizing with potassium should begin from the beginning of the growing season, at the stage of formation of 5 leaves, in combination with nitrogen and phosphorus. It is most convenient to use azofoska for this purpose. In the future, potassium is applied approximately 5–7 times during the entire growing season, the amount depends on the initial quality of the soil.
As a guide, potassium fertilizers should be applied once every 3 weeks; if necessary, phosphorus is added along with potassium, which promotes the formation of ovaries and fruits, improves their aesthetics and quality, and affects the quantitative indicators of the harvest in the direction of increase.
