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The difference between potassium nitrate, potassium sulfate and potassium chloride?

The difference between potassium nitrate, potassium sulfate and potassium chloride?

Issue Time:2021-04-05
Potassium nitrate, potassium sulfate, and potassium chloride are all potash fertilizers. They contain the same ingredients but have very different uses. Would you like to know the difference between potassium nitrate, potassium sulfate, and potassium chloride?


Potassium nitrate is a colorless crystal with low hygroscopicity, relatively easy to agglomerate, good physical properties, easy to apply, and is a good water-soluble potassium fertilizer. Potassium nitrate is a chlorine-free potassium and nitrogen compound fertilizer. The total content of phytonutrient potassium and nitrogen can reach about 60%, and it has good physical and chemical properties.

Potassium nitrate contains 13.5% of nitrate nitrogen and 46% of potassium; it is a chemically neutral and physiologically neutral fertilizer, with good water solubility, and long-term application will not cause soil acidification.

It is suitable for fruit tree young fruit expansion stage to early coloring stage, which can promote the expansion of pulp cells. Because it contains nitrate nitrogen, it is not recommended to use it in the later stage of coloring, which will easily cause blueness.


Theoretically 54% potassium content, generally 50%; it is a chemically neutral, physiologically acidic fertilizer with good water solubility, but long-term use will increase soil acidification. It is suitable for grapes from late coloring to fruit maturity to promote fruit growth. The powder is colored to increase the sweetness of the fruit.

Potassium Chloride

Potassium chloride is one of the most widely used potash fertilizers in the world, accounting for more than 90% of all potash fertilizer consumption. Potassium chloride is not only used directly as potash fertilizer or as a basic fertilizer for blending fertilizers, but also as the basic potassium source for the production of chlorine-free potassium fertilizers such as potassium sulfate, potassium nitrate or potassium phosphate.

Pure potassium chloride is a white shiny crystal. Commercial potassium chloride has a pale yellow, brick red or white appearance, crystal or granular, low free water content, and a certain degree of hygroscopicity.

The difference between potassium nitrate, potassium sulfate and potassium chloride

1. Comparison of the appearance of fertilizer

Potassium nitrate, in appearance, is a small colorless crystal (looks like white), but it has strong moisture absorption, so it is prone to agglomeration of fertilizers during long-term storage.

Potassium sulfate is also a colorless crystal in appearance (looks like white). It has relatively low moisture absorption, so under normal circumstances, the problem of fertilizer agglomeration does not occur.

Potassium chloride is mostly white or light yellow or brick red crystals and particles in appearance. It has a certain degree of moisture absorption, but its moisture absorption ability is not too strong.

2. Comparison of nutrient content of fertilizers

Potassium nitrate contains both potassium and nitrogen, and the nitrogen contained is nitrate nitrogen that can be quickly absorbed and utilized by crops. The potassium content is generally 46%, and the nitrate nitrogen content is generally 13.5%.

Potassium sulfate contains both potassium and sulfur. The potassium content is generally about 50%, and the sulfur content is generally about 18%. It should be noted that the potassium content in potassium sulfate fertilizers is generally not fixed. The potassium content added to the potassium sulfate produced by different manufacturers is different. The specific potassium content depends on how much potassium is added during the production of the product (the outer packaging will have a clear text mark ).

Potassium chloride contains potassium and chlorine. The potassium content is generally about 50-60%, and the chlorine content is about 45%. Although its potassium content is very high, its production process is simple, and it is used to produce potassium sulfate It is the basic raw material of potash fertilizers such as potassium nitrate and potassium nitrate, so it is a kind of potash fertilizer with lower use cost in potash fertilizer.

3. Comparison of acidity and alkalinity of fertilizers

Potassium nitrate is a neutral fertilizer, potassium sulfate is an acid fertilizer, and potassium chloride is a neutral fertilizer. Neutral fertilizers, such as potassium nitrate and potassium chloride, will not change the pH of the soil after use, while long-term use of acidic fertilizers can easily cause soil acidification problems, such as potassium sulfate.

4. Comparison of absorption speed after using fertilizer

After applying potassium nitrate, potassium sulfate, and potassium chloride to crops, under the same environmental conditions, the crops absorb potassium nitrate faster, potassium sulfate absorbs in the middle, and potassium chloride absorbs faster Slow, in other words, the speed of effect is potassium nitrate>potassium sulfate>potassium chloride.

5. Comparison of purchase price and usage cost

If you are a farmer who frequently uses potash fertilizer, you should know that the prices of the three types of potash fertilizers on the market are: potassium nitrate is more expensive than potassium sulfate, and potassium sulfate is more expensive than potassium chloride. Therefore, in terms of the cost of potash fertilizer, potassium nitrate>potassium sulfate > Potassium chloride.