How is potassium added to fertilisers?

Potassium is added to fertilisers in the form of potassium salts, such as potassium chloride, sulphate, or nitrate.

Potassium is a vital nutrient for plant growth and is often found in insufficient quantities in the soil. To supplement this, potassium is added to fertilisers to enhance the nutrient content of the soil and promote healthy plant growth. The process of adding potassium to fertilisers involves the use of potassium salts. These salts are typically potassium chloride, potassium sulphate, or potassium nitrate.

Potassium chloride, also known as muriate of potash, is the most commonly used potassium salt in fertilisers. It is obtained from natural sources such as sea water or brine wells and is processed to remove impurities. The resulting product is a white crystalline salt that is easily soluble in water, making it an ideal source of potassium for plants.

Potassium sulphate, also known as sulphate of potash, is another potassium salt used in fertilisers. It is preferred for crops that are sensitive to chloride, such as fruits and vegetables. It is produced by reacting potassium chloride with sulphuric acid, resulting in a product that is lower in potassium content than potassium chloride but is free of chloride.

Potassium nitrate, also known as saltpetre, is a third type of potassium salt used in fertilisers. It is produced by reacting potassium chloride with nitric acid. This results in a product that not only provides potassium but also nitrogen, another essential nutrient for plants.

In all cases, the potassium salts are mixed with other nutrients and materials to create a balanced fertiliser that can provide a range of nutrients to the soil. The exact composition of the fertiliser will depend on the specific needs of the soil and the crops being grown.