Content
Potassium, along with nitrogen and phosphorus, is vital for tomatoes. It is part of the cell sap of plants, promotes accelerated growth and rooting of young tomatoes. In the process of growing crops, gardeners repeatedly resort to using various potash fertilizers. It can be complex mixtures purchased ready-made or obtained by combining various substances. Fertilizers containing only potassium can be used to compensate for the lack of this microelement. Potassium fertilizers for tomatoes can be used in the form of root and foliar fertilizing, and the result of adding this microelement will not take long to arrive.
Potassium value for tomatoes
Tomatoes have a constant need for potassium. Plants consume the microelement in large quantities during the formation of 3-4 leaves. At this time, seedlings should be fed with potassium fertilizers. The second mandatory stage of feeding should allow the plants to take root better in new conditions. In this case, fertilizers are applied a week before the intended planting.Subsequently, plants need potassium from the moment the ovaries form until the end of fruiting.
Sufficient amount of potassium in the soil:
- allows the leaves and shoots of the plant to develop better;
- promotes rapid rooting of tomatoes after transplantation;
- increases the proportion of dry matter in fruits;
- improves the taste of vegetables. Without potassium, tomatoes ripen sour with insufficient sugar content;
- promotes timely ripening of vegetables;
- makes tomatoes invulnerable to various fungal and bacterial diseases;
- allows plants to withstand low temperatures and weather disasters.
Thus, without potassium it is impossible to grow tomatoes. This mineral can be added to the soil regularly at intervals of 10-15 days. Excess potassium in tomatoes can be observed very rarely, but every gardener should know the symptoms of potassium deficiency in order, if necessary, to take timely measures to prevent the development of the problem.
Micronutrient deficiency
Potassium deficiency in tomatoes can be diagnosed based on changes in leaves and fruits. The main symptoms of a deficiency of this microelement are:
- The appearance of a dry edge on the leaves. Its color is initially light, but over time it acquires a brown tint. It is worth noting that drying begins from the tip of the leaf blade and gradually spreads along the entire perimeter of the leaf.
- Tomato ovaries are formed in insufficient quantities.
- Vegetables ripen unevenly.
- On the fruits you can see unripe spots at the stalk.
Based on these characteristic signs, a caring owner should detect the problem as early as possible and take all necessary measures to eliminate it, namely, spray or water the plant roots with potassium fertilizers.
Potash fertilizers
Tomatoes have a negative attitude towards chlorine, so the choice of fertilizers for the crop must be approached with special care. So, to feed tomatoes with potassium, you can choose one of the following fertilizers:
Potassium monophosphate
This fertilizer is two-component, contains 33% potassium and 50% phosphorus. This potassium-phosphorus fertilizer for tomatoes is excellent for feeding after transplantation or at the time of fruit formation and ripening. The advantage of potassium monophosphate is that the tomato fertilizer is highly soluble in water, so it can be used for root and foliar feeding of tomatoes.
To spray tomatoes, potassium monophosphate is diluted with water to obtain a concentration of 1-2%. You can water the tomatoes at the root with a solution of the same concentration. Fertilizer consumption assumes the use of 10 liters of solution per 4 plants or 1 m2. It is recommended to use fertilizer based on potassium monophosphate no more than 2 times during the entire growing season.
Potassium nitrate
Potassium nitrate can be found under another name - potassium nitrate. The fertilizer contains 3 components at once: nitrogen (14%), potassium (46%) and phosphorus (7%). This complex composition allows you to feed tomatoes not only with potassium, but also with nitrogen to activate growth. It is rational to use fertilizer during the period of ovary formation.
The fertilizer is highly soluble in water. It is used for foliar and root feeding of tomatoes. For spraying, prepare a solution with a concentration of 0.5 to 4%.This variation, allowed by the manufacturer, allows the gardener, depending on the composition of the soil and the condition of the plant, to independently choose the rate of application of minerals. By the way, experienced gardeners recommend adding 10 g of the substance per bucket of water. This is quite enough to saturate the tomatoes with the necessary substances by spraying.
To water tomatoes at the root, add 10-20 g of potassium nitrate to a bucket of water. This volume of liquid should be enough to water plants on 1 m2 soil.
Calimagnesia
Calimagnesia combines potassium sulfate and magnesium. It is worth noting that magnesium is also necessary for the life of tomatoes. On sandy soils, plants may lack this microelement, which can be compensated with potassium magnesia.
A symptom of magnesium deficiency is leaf discoloration. The leaf veins remain green, but parts of the leaf blades between the veins turn yellow, then acquire a reddish or purple tint. Magnesium deficiency appears starting from the lower leaves.
Thus, it is rational to use potassium magnesium if there is a lack of potassium or magnesium. Potassium magnesia should not be used regularly as the main fertilizer for tomatoes.
All of the listed potash fertilizers can be purchased at a specialized agricultural store. Their use must strictly comply with the instructions given so that the increased concentration of substances does not harm the tomatoes. To feed tomatoes, you should not use the same fertilizer throughout the entire growing period; it is much better to use different fertilizers depending on the stage of growing tomatoes.
You can find another potash fertilizer on sale: potassium chloride. It should not be used to feed tomatoes, since the substance contains harmful chlorine.
Ash as a food source
Wood ash is an affordable, environmentally friendly fertilizer that is always at hand. It can be obtained by burning solid wood, branches, sawdust, and straw. If there is a stove in the house or bathhouse, then there are problems with the preparation ash does not arise at all.
The ash contains a whole range of microelements necessary for tomatoes. Their concentration largely depends on what was the source of the raw material:
- The largest amount of potassium is contained in straw combustion products (30%). Coniferous ash contains no more than 5% of this mineral; valuable birch trees make it possible to obtain ash containing 13% potassium.
- Calcium occupies a large part in the composition of wood ash. For example, when burning pine or birch firewood, the ash contains about 40% calcium;
- Ash of any origin contains no more than 6% phosphorus.
In addition to essential microelements, wood ash contains important substances such as magnesium and manganese. Using ash to feed tomatoes allows you to saturate the plants with all the necessary minerals, except nitrogen, so wood ash is used as an independent fertilizer or in combination with nitrogen fertilizers and organic matter.
Ash in dry form can be embedded in the soil during autumn and spring digging. You can also sprinkle a small amount of it on the tomato tree trunk, followed by loosening and watering the soil. Liquid root and foliar fertilizers are prepared based on ash:
- For watering under the root, an infusion is prepared from the ash. The substance is added to a bucket of water in a volume of 1-2 glasses. After mixing, the resulting mixture is infused for 24 hours and used for watering, 500 ml for each bush;
- Spray the tomatoes with ash decoction. To do this, 300 g of wood ash is boiled for 20 minutes. After preparation, the broth is cooled and filtered. Before use, the decoction is diluted in 10 liters of water. Add a little, 30-40 ml, liquid soap to the resulting mixture. They use a product for spraying leaves to feed and protect against late blight, slugs and other diseases and pests.
Thus, ash is a natural, affordable fertilizer with a high content of potassium, calcium, and phosphorus. Using ash is quite simple, and the effect of its use is always positive. Use ash fertilizers on a leaf or under the root can be done regularly once every 3-4 weeks.
You can find out some other details about the use of ash as fertilizer in the video:
Cement dust
Surprisingly, cement dust can also be a good potassium fertilizer for tomatoes, since it contains absolutely no chlorine, and the concentration of potassium in the substance reaches 30%. Based on cement dust, a solution is prepared for watering plants at the root. The substance is highly soluble in water and is easily absorbed by tomatoes.
Complex fertilizers with potassium
To feed tomatoes with potassium, you can use not only potassium fertilizers, but also complex ones, which will contain, in addition to this microelement, additional ones necessary for the growth and development of plants.Such fertilizers can be bought in specialized stores or prepared independently.
Ready-made complexes
When you go to any agricultural store, you can find a lot of fertilizers with completely different price tags. They all contain the same complex of basic substances: nitrogen, potassium, phosphorus, in different concentrations. Among the most affordable, but no less effective complex fertilizers, the following should be highlighted:
Potassium sulfate
Potassium sulfate is a three-component fertilizer with a high content of potassium and sulfur. It is also called potassium sulfate. The concentrations of substances in the fertilizer are 50% potassium, 46% sulfur and 4% acid phosphorus (7% neutral phosphorus). Potassium sulfate is used on alkaline soils. If the soil is highly acidic, it cannot be used.
Potassium sulfate is used to water plants at the roots. In this case, the concentration of the substance should be no more than 0.1% (1 g of substance per 10 liters of water). Such a low concentration will slightly increase the acidity without harming the plants.
It should only be used on alkaline soils when signs of potassium deficiency appear. Potassium sulfate also helps fight late blight on tomatoes.
Potassium humate
This unique fertilizer contains all the necessary mineral microelements and a lot of other substances that promote the accelerated growth and development of tomatoes. Thus, at least 80% of the substance is humic acids. They improve the chemical composition and physical properties of the soil, increasing crop productivity.
Potassium humate can be used at various stages of growing tomatoes:
- To soak the seeds, prepare a solution by adding 20 ml of the substance to a glass of water. Soaking for 24 hours activates the growth of planting material and disinfects the surface of the grains;
- Watering tomatoes at the root can be done three times during the entire growing season. To do this, dilute 50 ml of the substance in a bucket of water.
- For foliar feeding, use a solution of the same concentration as for root watering.
- Watering the soil with potassium humate during the digging process allows you to restore its fertility. For these purposes, the fertilizer is diluted in a ratio of 500 ml per 10 liters of water.
Potassium humate is a natural fertilizer that can be used to feed tomatoes in various ways many times throughout the entire growing period.
Ammofoska
This complex, granular fertilizer contains nitrogen, potassium and phosphorus in approximately equal proportions - 15% each.
You can feed tomatoes with this complex, three-component fertilizer at various stages of the growing season. As a rule, ammophoska is used three times: added to the holes when planting seedlings, and the plants are watered with the solution during the flowering period and during the period of active fruiting. Prepare a solution of ammophoska by dissolving 10 tablespoons of the substance in a bucket of water.
Nitrophoska
The fertilizer also contains 3 main components, with the amount of nitrogen in the mixture reaching 52%. Potassium and phosphorus in this fertilizer are in equal proportions, approximately 24%.
It is recommended to use fertilizer for feeding tomato seedlings, as well as when observing slow plant growth. The granules of the substance are highly soluble in water, so for feeding tomatoes it is recommended to prepare a solution: 1 spoon per 10 liters of water.
In addition to the above, well-known fertilizers, you can find complex substances that are also mixtures of 3 components, for example “Universal”, “Kemira Lux”, “Ava” and others. They must be used strictly in accordance with the instructions.
Do-it-yourself universal mixtures
You can prepare a universal fertilizer for feeding tomatoes containing potassium, nitrogen and phosphorus yourself by mixing several one-component substances. Experienced farmers often use the following recipes:
- Add superphosphate (40 g), as well as urea (15 g) and potassium sulfate (15 g) to a bucket of water. Superphosphate must be soaked in water one day before using the fertilizer. Immediately before use, add two other components to the solution.
- Add 80 g of ash and 20 g of ammonium nitrate to 8 liters of water. After dissolution, the mixture is poured over the tomatoes at the root.
When independently preparing complex fertilizers for feeding tomatoes, you can use organic substances:
- Dissolve 200 g of mullein or liquid chicken manure in a bucket of water. Add one teaspoon each of potassium sulfate and superphosphate to the resulting mixture.
- Add 150 ml of mullein and a spoonful of nitrophoska to a bucket of water.
Conclusion
With regular use of complex fertilizers, tomatoes will not experience a deficiency of minerals, including potassium. However, in some cases, soil depletion, increased amounts of calcium, or some other factors cause symptoms characteristic of potassium starvation. In this case, it is necessary to fertilize the tomatoes with potassium fertilizers, the list and method of use of which is given above in the article.
