Potash fertilizers: application and application, types
Houseplants Published: July 30, 2012 Reprinted: Last edits:
For both gardeners and florists, it is difficult to overestimate the importance of potassium for the growth and development of plants. But although potassium is one of the most essential mineral elements, unlike other useful substances, for example, phosphorus or nitrogen, it is not included in the organic composition of plants, so the need to use potash fertilizers is obvious.
Why do plants need potassium
From my own experience, I was convinced that potash fertilizers help plants become more hardy, resistant to droughts and frosts, they provide faster growth and formation of fruits.
If “burnt” edges and a bluish tinge or small “rusty” marks appear on the leaves, and the buds and inflorescences become lethargic and frail, then you can, without hesitation, diagnose a lack of potassium in the plant.
In large quantities, potassium is needed for sunflowers, buckwheat, beets (including sugar), potatoes and other vegetables. Rye, wheat and other grains consume less potassium.
Correct fertilization will help the plant to acquire many useful properties, increase immunity to diseases and natural phenomena, while inept use of fertilizers can lead to various unpleasant consequences, up to the death of plants. The use of fertilizers requires great care and attention. First of all, it is necessary to consider the type of plant and the composition of the soil. In heavy clay soils there is always more potassium than in light sandy soils, while the poorest potassium soil is peat. It should be borne in mind that potash fertilizers are chloride and sulfate, and each of these types has its own purpose, its advantages and, unfortunately, disadvantages.
Types of potash fertilizers and their features
Chloride potash fertilizers outwardly they look like pink crystals. In general, these fertilizers have a positive effect on plants: they increase yields, increase immunity to diseases and pests, promote good tying of tubers and increase their shelf life, as well as extend the life of the plants themselves. But, unfortunately, there is also an important negative nuance - the chlorine content. Since interaction with chlorine harms plants, the soil should be fertilized long before sowing, and fertilizer must be applied in a strictly defined amount. Frequent or abundant use of chloride fertilizers negatively affects the condition of the soil: the pH may shift towards the acidic side. Potassium chloride can only be used on light soils, for example, sandy: harmful chlorine is washed out from such soil by precipitation, and useful potassium remains and is easily absorbed by the soil. It should also be remembered that in no case should potassium chloride be used to fertilize tomatoes, potatoes and indoor plants.
A much wider list of positive qualities in potassium sulfate (potassium sulfate)... In addition to sulfur and potassium, such fertilizers contain magnesium and calcium, which has a beneficial effect on plants. In addition, potassium sulfate can be used at any time of the year and on any soil. It is suitable for all plants, including those that do not tolerate chlorine: potatoes, tomatoes, peppers, peas, all berry crops, as well as indoor plants.
The choice of fertilizer for indoor plants requires great care and attention, and the application requires extreme precision in dosage. First of all, it should be understood that only a healthy plant can be fed during the period of its intensive growth. Flowering plants, such as calla lilies, hydrangeas, anthuriums, streptocarpuses, brovallia, gerberas, spathiphyllums, are more in need of potassium.
However, despite the indisputable advantages of potassium fertilizers, it is necessary to remember how important moderation in dosage is, since both a deficiency and an excess of potassium are sometimes fraught with serious consequences. When the soil is oversaturated with potassium, the plants lose their high immunity and all acquired positive properties, and, as a result, turn yellow, wither, get sick, their leaves and shoots fall off.
To increase the efficiency of potash fertilizers, I recommend mixing them with phosphorus and nitrogen fertilizers, and do this immediately before fertilizing.
Potash fertilizer is one of the most essential elements of plant mineral nutrition. Potassium is not a part of organic compounds in a plant, but is in plant cells in ionic form in the form of soluble salts of cell sap and forms partly adsorption complexes with cytoplasmic colloids. Most of all potassium is found in the young vital parts of the plant. With its lack in the nutrient medium, it is outflowed from older organs and tissues to young growing ones, where it is reused.
In the plant organism, potassium has various functions. It has a positive effect on the physical state of cytoplasmic colloids, increases their hydration, swelling and viscosity. This is of great importance for normal cell metabolism, as well as for increasing plant resistance to drought. With a lack of potassium, plants lose turgor faster and wither. Potassium has a positive effect on the intensity of photosynthesis, oxidative processes and the formation of organic acids in the plant; it is involved in carbohydrate and nitrogen metabolism. If there is a lack of potassium in the plant, then protein synthesis is inhibited, as a result, all nitrogen metabolism is disrupted. Potassium deficiency is especially noticeable when plants are fed with ammonium nitrogen. With its lack, the transformation of simple carbohydrates into more complex ones is delayed. Potassium also increases the activity of enzymes involved in carbohydrate metabolism, in particular sucrase and amylase. Under the influence of potassium, the frost resistance of plants increases, which is associated with a high content of sugars and an increase in osmotic pressure in the cells.
If there is enough potassium in plants, then their resistance to various diseases increases. Potassium also contributes to the development of mechanical elements of vascular bundles and bast fibers, therefore, it has a positive effect on the strength of the stems and the resistance of plants to lodging, on the yield and quality of flax and hemp fibers. With a lack of potassium, the development of reproductive organs is inhibited - the development of buds and rudimentary inflorescences is delayed, the grain turns out to be puny, with reduced germination.
Potassium consumption by different crops, its amount in the plant
Outward signs of potassium starvation appear in plants when their potassium content is 5 times lower than normal. The tips and edges of the leaves turn brown, small rusty spots appear on the leaf blade.
There is more potassium in vegetative organs than in seeds, tubers and roots. The potassium content in the leaves of sunflower, tobacco and sugar beet is 6% on a dry weight basis, in cereal straw 1.5%, in cabbage up to 0.5%.
Of all the ash elements, potassium is consumed by plants in the greatest amount. Especially a lot of potassium is absorbed by sunflower, beet, potatoes, buckwheat, cabbage and other crops, less - wheat, rye, oats and barley.
Forms of potassium and its content in soil
In different soils, the amount of potassium varies from 0.5 to 3% and depends on their granulometric composition. The clay fraction of the soil contains the most potassium, and therefore heavy loamy and clayey soils are richer in potassium than sandy and sandy loamy soils.
Potassium compounds according to the degree of mobility and availability for plants can be divided into the following groups:
1. Potassium, which is part of strong aluminosilicate minerals, mainly feldspars (orthoclase) and micas (muscovite, biotite).
Potassium feldspars for plants is inaccessible. But under the influence of water, changes in the temperature of the environment and the activity of soil microorganisms, there is a gradual decomposition of these minerals with the formation of soluble potassium salts.
2. Exchangeable potassium, absorbed by soil colloids, is 1.5% of the total content of this element in the soil. He plays the main role in plant nutrition. The good availability of exchangeable potassium for plants is due to its ability, when exchanged with other cations, to easily pass into a solution, from which it is absorbed by plants. When plants assimilate potassium from the solution, new portions of it pass from the absorbed state into the soil solution. With the use of exchangeable potassium, this process slows down, and the remaining potassium is increasingly held in the absorbed state.
The content of exchangeable potassium can serve as an indicator of the degree of availability of assimilable potassium in the soil. Typical chernozems and serozem soils are richer in exchangeable potassium than sod-podzolic soils, especially sandy and sandy loam soils.
3. Water-soluble potassium is represented by various salts dissolved in soil moisture (phosphates, nitrates, sulfates, chlorides, potassium carbonates), which are directly assimilated by plants. Its content in the soil is insignificant, since from a solution potassium immediately passes into an absorbed state and is consumed by plants.
Water-soluble potassium in some soils can be absorbed in a non-exchangeable form, as a result of which its availability for plants is reduced. Non-exchangeable fixation of potassium is strongly expressed in chernozems and gray soils, especially when they are alternately moistened and dried.
Grain crops contain more potassium in straw than in grain, while potatoes and beets contain more potassium in tops than in tubers and roots. With a more complete use of plant waste in feed and bedding for cattle, most of the potassium with manure returns to the soil.
Classification of potash fertilizers
The range of potash fertilizers produced is dominated by highly concentrated forms - potassium chloride and 40% potassium salt. Potassium sulfate is produced in limited quantities. Also produced are magnesium-containing potash fertilizers - potassium magnesium and potassium chloride electrolyte. Part of the potassium will be included in the complex fertilizers. In agriculture, raw potash salts and cement dust are used as potash fertilizers.
Crude potassium salts are obtained by grinding natural potassium salts. They are characterized by a low potassium content and a large amount of impurities, which, in turn, increases the cost of transporting and applying these fertilizers.
Of the crude potassium salts, sylvinite and kainite are the most common. They contain a large amount of chlorine, which also limits their use.
Sylvinite is produced in coarse grinding and is a mixture of large crystals of white, pink, blue or brown color. It is slightly hygroscopic. If you store it in a humid room, then it can become damp, and it cakes when dried. It is introduced as the main fertilizer in autumn for autumn cultivation. The chlorine contained in it is partially washed out into the lower layers of the soil, while potassium is absorbed by the soil. The high sodium content in sylvinite is beneficial for crops such as beets, fodder and table roots.
Cainite is obtained by grinding cainite or cainite-langbeinite rock. Cainite is used as the main fertilizer. The application of kainite under root crops, cabbage, sugar beets, clover and other crops gives good results, especially on light soils.
Industrial potash fertilizers
Industrial potash fertilizers include the following: potassium chloride, potassium sulfate, potassium magnesium, potassium chloride electrolyte.
Potassium chloride is obtained by separating calcium, chlorine and sodium, which is based on their different solubility with increasing temperature. This method is called the recrystallization method. Product granulation improves the physical properties of the fertilizer.
Potassium chloride is the main potash fertilizer. It contains 5 times less chlorine than sylvinite. It is used for all crops and on any soils.
40% potassium salt is obtained by mechanical mixing of potassium chloride with finely ground sylvinite or kainite. In terms of its properties and composition, it occupies an intermediate position between potassium chloride and sylvinite. Potassium salt is most effective for sugar beets and fodder root crops. For crops that are sensitive to excess chlorine, it is less suitable than potassium chloride. Potash salt is used as the main fertilizer with deep plowing under the plow, preferably from autumn under the plow.
Potassium sulfate is a grayish crystalline salt that is soluble in water. It has good physical properties, is non-hygroscopic and does not cake. Potassium sulfate can be used on any soil and under all crops, but it is especially recommended to use it under crops that are especially sensitive to chlorine. These crops include grapes, citrus fruits, flax, tobacco, potatoes.
Potassium magnesium is obtained in small quantities from natural sulfate potassium salts by recrystallization. Potassium is a good fertilizer for crops that are sensitive to chlorine and consume a lot of magnesium along with potassium. These crops include flax, potatoes, and clover.
Potassium chloride electrolyte is obtained in the production of magnesium from Solikamsk carnallite. It is used as the main fertilizer when applied from autumn for all crops.
Potash fertilizers are readily soluble in water; when applied to the soil, they quickly dissolve and interact with the soil absorbing complex.
On soils of heavy and medium granulometric composition, potash fertilizers should be applied in autumn for autumn cultivation. They are located in a moist soil layer, where the bulk of active roots develops, and therefore potassium is better absorbed by plants. On light soils, where potassium leaching is possible, it is advisable to apply fertilizers in the spring under the cultivator.
Potassium fertilizers are physiologically acidic salts, but their acidity is less, and it manifests itself in more noticeable amounts only with prolonged use of these fertilizers for crops that consume a lot of potassium. In a sharp form, acidification is observed with the systematic application of large doses of potash fertilizers. To prevent the negative impact of potash fertilizers, it is necessary to liming the soil and apply calcium-containing nitrogen and phosphorus fertilizers.
Effective use of potash fertilizers
Potash soils are effective on light sandy, sandy loam and peaty soils. These soils are poor in potassium, and the application of potash fertilizers greatly affects crops. On peatlands containing a lot of nitrogen, the application of potash fertilizers gives a tangible result. An important condition for the effective use of potash fertilizers is the provision of plants with phosphorus and nitrogen. On soils poor in nitrogen and phosphorus, the introduction of potash fertilizers will not give the desired effect. On loamy and clayey, as well as sod-podzolic soils, containing a lot of potassium, the need for it in crops is manifested with the simultaneous application of nitrogen and phosphorus fertilizers. On potassium-rich soils (such as chernozem soils), the need for this element arises only in crops that need a lot of it (sunflower, corn, sugar beet).On salt licks, which are rich in potassium, potash fertilizers do not give an effect, and their application leads to soil salinization.
With the constant use of phosphorus and potash fertilizers, the effectiveness of the latter increases.
To determine the doses of potassium, they are guided by the size of its consumption with the planned crop yields and the level of soil supply with mobile potassium. With a high supply of potassium, the need for potash fertilization decreases. In conditions of sufficient potassium nutrition, there is a lower susceptibility to diseases and damage by pests, an increase in resistance to lodging, frost and high temperatures, unfavorable conditions of the water regime.
Balanced potassium nutrition of plants contributes to obtaining high quality products, reduces losses during storage. When there is a sufficient amount of potassium in the soil, plants use moisture more economically. To control the correct doses of potash fertilizers that are used in crop rotation, it is advisable to determine the potassium balance. In this case, it is necessary to take into account the intake and use of potassium manure. On soils with a heavy granulometric composition, it is possible to add potash fertilizers to the reserve for four years. With this application of fertilizers in crop rotation, taking into account the composition of cultivated crops, it makes it possible to rationally use equipment, storage facilities, and more flexibly to maneuver the timing of agrotechnical work.
With the annual application of potash fertilizers on cohesive soils, it is better to apply them in the fall, and on light soils they need to be applied under pre-sowing treatment in the spring or partially in top dressing. In meadows with haymaking and especially pasture use of grass stand, potash fertilizers must be applied in fractional manner in order to avoid excessive concentration of potassium in the forage and its depletion in magnesium. On limed soils, the need for potash fertilizers increases. On light sandy and sandy loam soils, magnesium-containing potassium fertilizers are especially effective.
Nitrogen fertilizers and their application
Nitrogen is an essential nutrient for plants. A sufficient amount of nitrogen in the soil contributes to the increase and quality of the crop. Nitrogen fertilizers are used to feed vegetables (potatoes, tomatoes, beets, carrots, cucumbers), berries (strawberries, strawberries), garden trees and shrubs (cherries, currants, raspberries, plums, apricots). Fertilizer rate for top dressing per 1 sq. m is 3-5 g.
Ammonium nitrate - coarse white-pink salt, nitrogen content 35-36%. It is quickly absorbed and enhances plant growth. Storage conditions: waterproof container and dry place (fertilizer quickly absorbs moisture and cakes).
Urea (urea) - characterized by an increased nitrogen content (46%) and gradual assimilation by the soil. Top dressing with urea is best done in the spring at a rate of 20-22 g per 1 sq. m.
Ammonium sulfate - crystalline salt with 21% nitrogen content. Suitable for feeding in spring and autumn in the amount of 25 g per 1 sq. m, is slowly washed out of the soil.
It is recommended to apply nitrogen fertilizers in small quantities, but several times per season.
This fertilizer contains up to 29% potassium and about 9% magnesium. It is most effective on light soils (sandy and sandy loam).
Potassium in combination with magnesium helps to increase plant immunity, resistance to recurrent frosts and winter frosts, accelerates ripening and increases the yield. Kalimagnesia is ideal for grapes, potatoes, tomatoes, grains and legumes, radishes and onions.
The application rate is from 30 to 60 g per 1 m 2 in the autumn and spring periods. In the summer, the dosage should be 9-11 g per 1 m 2.
Kalimagnesia is indicated for application also during the flowering period and the beginning of berry setting.
It is appropriate to add potassium salt to sandy, sandy loam, peat soils - there the lack of potassium is most often manifested.
When and what plants need
The need for certain nutrients in different cultures is different, but a general pattern still exists. So, at the moment before the formation of the first true leaves, all young plants need more nitrogen and phosphorus, their lack at a given period of development cannot be replenished at a later date, even with enhanced feeding - the depressed state will remain until the end of the growing season.
During the period of active growth of vegetative mass by plants, nitrogen and potassium play a dominant role in their nutrition. At the moment of budding and flowering, phosphorus becomes important again. If at this stage foliar feeding is carried out with phosphorus and potassium fertilizers, the plants will begin to actively accumulate sugar in the tissues, which ultimately will have a positive effect on the quality of their harvest.
Therefore, using mineral fertilizers, you can not only maintain soil fertility at the proper level, but also regulate the volume of production from the cultivated area.
Potassium chloride. © seekpart Ammonium sulfate. © seekpart Ammonium chloride. © seekpart
Mineral fertilizers: nitrogen, potash, phosphorus, articles
Agrochemical fertilizers are widely used in horticulture and horticulture. Today we will consider potash fertilizers, in particular, potassium chloride and calcium.
Ammonium sulfate (Nh5) 2SO4 or other names - ammonium salt of sulfuric acid, ammonium sulfate - refers to crystalline, colorless, inorganic.
Nitrofoska is a well-known and frequently used nitrogen-phosphorus-potassium mineral fertilizer. The product is perfectly balanced.
Superphosphate is a mineral fertilizer formed during the breakdown of natural phosphates. The main component of fertilizer is phosphorus, which is necessary for.
Limestone flour helps to normalize the acidity of the soil, as well as create ideal conditions for the rapid and productive growth of any kind.
Phosphate fertilizers are essential for the proper development of plants at all stages of the growing season. Ammophos is one of the common ones.
Ammofoska is a complex fertilizer, which contains no chlorine and sodium. The composition is organically balanced for full cultural nutrition.
Potassium sulfate is used in the dacha farming as a fertilizer. The role of potassium in the development of agricultural crops is irreplaceable, since its ions coordinate metabolic processes in.
Phosphate fertilizers are what the names are. Water-soluble phosphorus fertilizers: description and application
All phosphorus-containing mineral fertilizers are divided into water-soluble, limited-soluble and insoluble (). The water-soluble group includes superphosphates:
Simple superphosphate. Contains 16-20% phosphorus in the form of dihydrogen phosphate and phosphoric acid. The composition also contains calcium, sulfur and traces of magnesium .. Double superphosphate. It is similar in composition to simple superphosphate, but the phosphorus concentration is doubled - up to 46-49% ..
Both substances are produced in granular form, easily form aqueous solutions, and in terms of the degree of phosphorus assimilation they are the best of all types of phosphorus fertilizers.
Superphosphates are used for the main application to the soil in spring and autumn, as well as for summer root dressing with solutions: