The difference between various high-potash fertilizers

There are a lot of mixed potassium fertilizers on the market, including potassium sulfate, potassium chloride, potassium nitrate, potassium dihydrogen phosphate, potassium humate, potassium fulvic acid, potassium carbonate, biological potassium, etc. Many farmers often confuse the concept of “potassium fertilizer”, resulting in a lot of wasted money. Plant protection experts have sorted out the common potassium fertilizer products on the market, as well as their advantages and disadvantages.

Detailed introduction of various potash fertilizers and production line

1. Potassium chloride

The national standard is GB20406-2006. It generally has three forms: powder, granules, and crystals. It is odorless, bitter, hard, and stable in the air. It generally contains 45-52% potassium, 18% sulfur, and ≤3% chloride ion. It has a long-lasting fertilizer effect. It is widely used in crops such as vegetables, fruit trees, tobacco, and tea trees that are sensitive to chloride ions. It is a more expensive high-quality sulfur-containing potash fertilizer.

• Advantages: low price, high potassium content, not easy to absorb moisture, and can provide sulfur.
• Disadvantages: dissolution absorbs heat, weak acidity, and is a physiological acidic fertilizer. The sulfur contained in it is easy to combine with calcium to form slightly soluble calcium sulfate, which can cause soil acidification and compaction after application.

2. Potassium sulfate

The national standard is GB20406-2007. It generally has four forms: powder, granules, and crystals. It is odorless, bitter, hard, and stable in the air. It generally contains 45-47% potassium, 18% sulfur, and ≤2% sulfate ion. It has a long-lasting fertilizer effect. It is widely used in crops such as vegetables, fruit trees, tobacco, and tea trees that are sensitive to chloride ions. It is a more expensive high-quality sulfur-containing potash fertilizer.

• Advantages: low price, high potassium content, not easy to absorb moisture, and can provide sulfur.
• Disadvantages: dissolution absorbs heat, weak acidity, and is a physiological acidic fertilizer. The sulfur contained in it is easy to combine with calcium to form slightly soluble calcium sulfate, which can cause soil acidification and compaction after application.

3. Potassium nitrate

The national standard is GB/T20784-2006, white or light-colored powder. The potassium content is generally 44.5%, and the nitrogen content is 13.5%. The chloride ion content is generally ≤1.5%. It is widely used and can be applied as a bottom application or as a liquid fertilizer for foliar spraying and drip irrigation. It is more expensive than potassium sulfate and potassium chloride. It is a high-quality and efficient potassium fertilizer containing nitrate nitrogen.

• Advantages: moderate price, good solubility, not easy to absorb moisture, neutral fertilizer, and the nitrate nitrogen provided is absorbed quickly.
• Disadvantages: dissolution absorbs heat and lowers ground temperature, and it is easy to cause the accumulation of nitrite in crops under adverse conditions (it is prohibited to use in organic agriculture). It is a nitrate, and there are certain safety hazards during storage and processing, and it requires high-demand process conditions to produce.

4. Potassium dihydrogen phosphate

There is no national standard for potassium dihydrogen phosphate. Its industry standard is HG2321-92. Its appearance is white crystalline or powdery. Its chemical properties are stable, odorless, tasteless, non-toxic, easily soluble in water, non-caking, and suitable for various applications. soil and crops. Generally, it contains 52% phosphorus, 34% potassium, and no nitrogen fertilizer. It is widely used for seed soaking, root soaking, medicinal seed dressing, irrigation, foliar spraying, drip irrigation, etc. It has significant effects on crops in accelerating slurry, promoting metabolism, resisting dry and hot winds, preventing lodging, and increasing yields. According to the Ministry of Agriculture’s Order No. 32 “Measures for the Administration of Fertilizer Registration”, genuine potassium dihydrogen phosphate is a product exempt from registration. Its price is much more expensive than potassium sulfate, potassium chloride, and potassium nitrate, and the current ex-factory price is more than 10,000 per ton. Therefore, when farmers buy in the market, they can clearly tell the authenticity and purity by calculating the cost.

• Advantages: It is not easy to absorb moisture and has a high total content of phosphorus and potassium. It is an essential raw material for current high-content powder water-soluble fertilizers.
• Disadvantages: It dissolves and absorbs heat. It is weakly acidic. It is a physiological acidic fertilizer. Phosphorus has poor mobility and is easy to be fixed. It can cause soil acidification and hardening after application.

5. Potassium humate

There are no national labels or industry standards for potassium humate, and each manufacturer only has corporate standards. Generally, the humic acid content is 40-70% (on a dry basis), the potassium content is about 8-11%, and the pH value is 9-10 (alkaline). It is a non-toxic, odorless, black powder. It is an organic potassium fertilizer and one of the most slow-acting organic solid fertilizers. It has strong adsorption, exchange, complexation and chelation capabilities. The humic acid contained in it has strong biological activity, improves the soil, stimulates growth, increases the content of available mineral nutrients in the soil, and improves their utilization. It is widely used as base fertilizer, top dressing and foliar fertilizer for various crops. At the same time, it is also a high-quality raw material for the production of organic and inorganic compound fertilizers.

• Advantages: Alkaline fertilizer can reduce soil acidity and has multiple functions, allowing nutrients to have both quick-acting and delayed-acting effects.
• Disadvantages: easy to absorb moisture and high price.

6. Potassium carbonate

Agricultural potassium carbonate is extracted from plant combustion ash, is physiologically alkaline, and is a loose, hot, quick-acting fertilizer. It contains 50% potassium carbonate and more than 35% potassium oxide, which can increase soil temperature and neutralize soil acidity.

• Advantages: high potassium content, alkaline, can reduce acidity and release CO2 after application, increase the concentration of CO2 in the local microenvironment, and enhance the intensity of photosynthesis.
• Disadvantages: easy to absorb moisture, easy to swell, difficult to preserve, and highly corrosive.

7. Bio-potassium

Bio-potassium is actually an agricultural microbial agent. The national standard is GB20287-2006, with an effective bacterial content of 200 million/gram and a validity period of 2 years. It is an excellent strain selected from silicate bacteria, cultivated and fermented through a special process. Some people also call it “potassium bacteria” and jelly-like Bacillus. It belongs to the category of microbial fertilizer, but it plays a great role in agricultural production and can release the nutrients solidified in the soil. At the same time, adding different carriers will also lead to different effects.