For crops, there is no best fertilizer, only the most suitable fertilizer. The type and characteristics of fertilizer are different, the method used and the effect after use will be different, which can also explain some problems very well, for example, some farmer friends often encounter and ask about the use of potassium fertilizer (potassium nitrate, potassium sulfate, potassium chloride) the use of potassium fertilizer: the same is the use of potassium fertilizer for crops to supplement potassium nutrients, some long branches slightly stem and leaves are faster, some puffed fruit speed is better, some fruit coloring is slower and even the colored fruit will return to green, some plots will acidify the soil after using potassium fertilizer, Some plots will have the phenomenon of burning seeds and seedlings after the use of potassium fertilizer, and some plots have no good results after using potassium fertilizer.
Crop growth is inseparable from fertilizer, the most important for the normal growth and development of crops and the largest amount of nitrogen, phosphorus, potassium three elements, especially for the planting of fruit trees, melons, eggplant fruits, underground stems and other crops of farmers and friends, must and should pay special attention to the use of potassium fertilizer. To a certain extent, all crops with solid fruits and long stems, the yield in the later stage of the crop is not high, and the quality is good or not, which is directly related to the right choice of potash fertilizer and whether it is used well or not.
At present, whether it is the most common potassium fertilizer on the market, or the potassium fertilizer that farmers often buy, or the potassium fertilizer that is often used on crops, there are three main types of potassium fertilizers that we commonly and commonly use - potassium nitrate, potassium sulfate, and potassium chloride. Although these three fertilizers are potassium fertilizers, all contain potassium oxide, can be a good supplement to the crop potassium fertilizer, but because they have different fertilizer characteristics, in the nutrient content, phh alkalinity, water solubility, absorption rate, efficiency rate, use method, applicable crop type, applicable growth stage, applicable soil conditions, use of taboos, etc., there are very big differences, for example, potassium nitrate added nitrate nitrogen, potassium sulfate added sulfur, potassium chloride contains chloride ions, etc.
In order to help you clearly understand the correct use of different potassium fertilizers and solve some of the problems often encountered in the use of potassium fertilizers, today's agricultural technology small back basket will specifically tell you about the differences between potassium nitrate, potassium sulfate, potassium chloride, these three kinds of potassium fertilizers, what are the best use skills and special precautions in soil crops. The comprehensive comparison results of potassium nitrate, potassium sulfate and potassium chloride are as follows:
First, the appearance of fertilizer contrast
Potassium nitrate is a small colorless crystal (looks white) in appearance, but moisture absorption is relatively strong, so it is prone to fertilizer agglomeration during long-term storage.
Potassium sulfate, in appearance is also a colorless crystal (looks white), it is relatively small moisture absorption, so in general, the problem of fertilizer agglomeration will not occur.
Potassium chloride, in appearance, is mostly white or light yellow or brick red crystals, particles, it has a certain moisture absorption, but the moisture absorption ability is not too strong.
Second, the nutrient content of fertilizer comparison
Potassium nitrate, potassium and nitrogen, and the nitrogen contained is the nitrate nitrogen that can be quickly absorbed and utilized by crops, of which the potassium content is generally 46%, and the nitrate nitrogen content is generally 13.5%.
Potassium sulfate, potassium and sulfur, potassium content is generally about 50%, the highest can reach 50-55% potassium content, sulfur content is generally about 18%. It should be noted that the potassium content in potassium sulfate fertilizer is generally not fixed, the manufacturer is different, the potassium content added by the production of potassium sulfate is different, and the specific potassium content is how much is added to the production of the manufacturer's product (the outer packaging will have a clear text label).
Potassium chloride, potassium and chlorine, potassium content is generally about 50-60%, chlorine content of about 45%, although its potassium content is very high, but its production process is simple, and is the production of potassium sulfate, potassium nitrate and other potassium fertilizers as the basic raw materials, so in the potassium fertilizer it belongs to the lowest cost of use of a kind of potassium fertilizer.
Third, the acidity and alkalinity of fertilizer comparison
Potassium nitrate is a neutral fertilizer, potassium sulfate is an acidic fertilizer, and potassium chloride is a neutral partial acid fertilizer. Neutral fertilizers do not change the pH of the soil after use, such as potassium nitrate and potassium chloride, and long-term use of acid fertilizers is likely to cause soil acidification problems, such as potassium sulfate.
Fourth, the absorption rate after using fertilizer is compared
After the potassium nitrate, potassium sulfate, potassium chloride three kinds of potassium fertilizer used on the crop, under the same environmental conditions, the crop absorption rate of potassium nitrate is the fastest, potassium sulfate absorption rate is centered, potassium chloride absorption rate is the slowest, in other words, the effective rate of potassium nitrate> potassium sulfate > potassium chloride.
Fifth, the purchase price and the cost of use comparison
If you often use potassium fertilizer farmers and friends should know that the price of the three kinds of potassium fertilizers on the market is: potassium nitrate is more expensive than potassium sulfate, potassium sulfate is more expensive than potassium chloride, so in the cost of potassium fertilizer use, potassium nitrate > potassium sulfate > potassium chloride.
Sixth, the comparison of usage methods
Potassium nitrate, can be used as bottom fertilizer, topdressing, flushing, foliar spraying, etc., especially with it for topdressing and foliar fertilizer spraying effect is the best, the use of bottom fertilizer in the cost of fertilizer is not as cost-effective as the use of lower price potassium sulfate, because it only contains nitrogen and potassium two elements, the use of generally need to be used with phosphate fertilizer.
Potassium sulfate can be used as a bottom fertilizer, topdressing, flushing, foliar spraying, etc., because its price is moderate and the effect is good, therefore, it is also the most commonly used potassium fertilizer when planting melons, vegetables and fruit trees, because it only contains potassium in the three elements, so it is generally necessary to use nitrogen fertilizer and phosphate fertilizer together.
Potassium chloride can be used as a bottom fertilizer (10-15 days in advance) and topdressing (after the seedlings grow), rarely spraying foliar fertilizers, and should be avoided as seed fertilizers, because the chloride ions in fertilizers are easy to cause crops to burn seeds or burn seedlings. In addition, because potassium chloride contains high chloride ions, therefore, if potassium chloride is used as a bottom fertilizer, it should be used 10-15 days before sowing or colonization, so that the chloride ions in the fertilizer penetrate into the deep soil with water in the shallow soil (reducing the harm of chloride ions), otherwise it is easy to lead to the problem of chloride ion burning seedlings after crop sowing or colonization.
7. Comparison of applicable soil conditions
Under normal circumstances, neutral fertilizers can be widely used on various types of soils, because it will not change the acidity and alkalinity of the soil after use; alkaline fertilizers cannot be used on saline-alkali soils (but can be used together with acidic fertilizers), otherwise the more they are used, the longer they are used, the more salinity of the soil is stronger; acidic fertilizers cannot be used on acidic soils (but can be used with alkaline fertilizers), otherwise the more they are used and the longer they are used, the heavier the degree of acidification of the soil. therefore:
Potassium nitrate can basically be used in various soil types, the amount of residue used in the soil is very small, and long-term use will not cause soil acidification problems, nor will it lead to the problem of increased salinity accumulation in the soil. Although potassium nitrate is very harmful to the soil, although its water solubility and use effect is very good, its fertilizer efficiency period is relatively short, so it is more cost-effective to use it for topdressing and foliar spraying. In addition, because potassium nitrate is very water-soluble, it is not suitable for use in paddy fields (such as rice fields) or areas with a lot of precipitation, otherwise it will cause the nitrate nitrogen in the fertilizer to be lost with a large amount of water white erosion.
Potassium sulfate because it contains sulfate ions that easily lead to soil acidification, so it can not be used on soil with high acidity or acidification (it is easy to form difficult water-soluble sulfates in soil), at the same time, potassium sulfate cannot be used on soil with large calcareous or calcium content, because the sulfate ions in fertilizer will react with calcium ions in the soil to form calcium sulfate that is difficult to dissolve and difficult to absorb by crops, in addition, potassium sulfate is not suitable for heavy water, poor drainage, poor water permeability and rice fields with strong reducivity. Otherwise, it is easy to cause iron poisoning or aluminum poisoning in crop roots, or a large number of residual sulfates in the soil will be reduced to hydrogen sulfide harmful to the roots, resulting in the problem of blackening and harming the root system of crops. However, the use of potassium fertilizer on floating mud fields and cold soaking fields will be better than the use of potassium chloride.
Although potassium chloride is a neutral acidic fertilizer, it can be used on most types of soil, but because it contains 1-3% sodium chloride, it is not suitable for use in saline soil, otherwise it is easy to lead to the accumulation of salt content in the soil, thereby aggravating the salinity problem of the soil or causing; if it is used for a long time, it will also cause the soil to slowly acidify, but the degree of acidification is not as strong as potassium sulfate. In general, the use of potassium chloride per acre should be controlled at about 8-10 kg, it is best to use it with lime or alkaline nitrogen and potassium fertilizers, and at the same time try to apply to the deep moist soil layer, and when used, neither seed fertilizer nor foliar spray fertilizer, which must be paid attention to.
In addition, because potassium chloride remains in the soil with strong chloride ion dispersion, it can constantly infiltrate and leach into the deep soil with water in the soil, so if potassium fertilizer is used in paddy fields (rice fields with strong reducivity), or potassium fertilizer is used on grass crops, potassium chloride will be more effective and less expensive than potassium sulfate!
Eighth, the comparison of applicable crop ranges
Leaving aside the crop growth period factors (the reasons will be explained to you later), potassium nitrate and potassium sulfate can be widely used in various crops, and are most suitable for use in crops that like potassium but avoid chlorine.
Potassium chloride because it contains more chloride ions (potassium chloride high chlorine type, medium chlorine type, low chlorine type), so it is most suitable for use in potassium and fine chlorine crops (such as cotton and hemp, etc.), but it is not suitable for potassium avoid chlorine or chlorine sensitive crops, otherwise it is easy to cause crops due to excessive absorption of chloride ions and fertilizer damage, or reduce the quality of crops, for example, chloride ions will reduce the sugar content of fruits, reduce the burning quality after tobacco harvest, increase the moisture content of potato crops underground stems, etc.
Note: (1) Crops that are not suitable for potassium chloride mainly include: tobacco, tea, ginger, sugarcane, sugar beet, sweet potato, potato, yam, lotus root, celery, spinach, rapeseed, amaranth, peas, cauliflower, kale, green onion, cucumber, tomato, lettuce, eggplant, pepper, grape, citrus, watermelon, strawberry, apple, pomegranate, mango, loquat, banana, apple, apple, peach, huanglian, panax notogins, purple yunying, etc. (2) Suitable for the use of potassium chloride crops mainly include: wheat at the 3-5 leaf stage, rice at the 3-5 leaf stage, large cabbage and rape at the 4-6 leaf stage, and other crops with strong chlorine tolerance include sorghum, millet, corn, cotton, etc.
In a word: the planting of melons, fruits and vegetables, all kinds of fruit crops, underground stem and tube crops, should try to avoid the use of potassium chloride, otherwise it is easy to reduce the quality of crops; planting grass field crops, you can use cheaper potassium chloride to reduce the cost of fertilizer.
9. Comparison of applicable crop growth periods
Because potassium nitrate contains 13 nitrate nitrogen (nitrogen) that can be directly absorbed and utilized by crops, it can supplement potassium fertilizer for crops at the same time, but also add nitrogen fertilizer to crops to promote the growth of seedling stems and leaves. Therefore, potassium nitrate is suitable for use before fruit coloring on the crop or during the growth period of stems and leaves, which can promote growth and promote fruit expansion and development, but after the fruit begins to color on the crop, it should avoid the use of potassium nitrate, if potassium nitrate is used in the middle and late stages of fruit coloring, it is easy to cause the crop stem to grow too much and affect the full expansion of the fruit tree, and the second is easy to cause the fruit to absorb too much nitrogen and the problem of greedy green growth, slow fruit coloring, and late ripening. In severe cases, it can also cause the fruit that has been colored on the crop to fade and turn blue. The agricultural technology basket also recommends here: when the crop begins to expand, it is recommended to use potassium nitrate to promote growth and expansion of the fruit, and after the crop begins to change color, it is recommended to use potassium sulfate to promote the expansion and coloring of the benton fruit.
Potassium sulfate, the applicability of crops is very extensive, because it only contains potassium (except sulfur), no chlorine, no nitrogen, so it can basically be used at all stages of crop growth, especially suitable for the flowering and fruiting stage of crops, the gestational ear filling stage, the underground tubers expansion and development period, the fruit expansion and color change period, etc. It is also the most used potash fertilizer when our farmers and friends plant melons and vegetables, orchard fertilization, etc.
Potassium chloride, because it contains chloride ions, so, in addition to chlorine sensitive or chlorine-avoidant crops, it is generally used to make bottom fertilizer before sowing crops of field grasses (such as rice, corn, sorghum, etc.) or to do topdressing at the 3-5 leaf seedling stage and panicle stage of grass crops.
It should be noted that potassium nitrate is a strong oxidant substance, in the face of high temperature, open flame or strong collision, extrusion, etc., it is easy to explode or induce fire problems (potassium sulfate is also one of the raw materials for the production of black powder), therefore, we should pay special attention to it when transporting or preserving potassium nitrate to prevent unexpected losses.
Final reminder: whether it is potassium nitrate, or potassium sulfate, potassium chloride, we can not blindly say which potassium fertilizer is good, which kind of potassium fertilizer is poor, the so-called "no best fertilizer, only more suitable fertilizer", the use of potassium fertilizer effect is not good, the key depends on the right choice of potassium fertilizer when planting fertilizer, the method used is not right, otherwise, potassium fertilizer you use no more has no good effect!
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