What is the Difference Between Muriate of Potash and Sulphate of Potash

Muriate of potash and sulphate of potash are two potassium fertilizers that are added to plants to improve their health. They increase disease resistance, improve fruit quality, and enhance water efficiency.

What is the difference between muriate of potash and sulphate of potash? Muriate of potash contains chloride as an additional element, while sulphate of potash contains sulfur as an additional element.

Key Areas Covered

1. What is Muriate of Potash 
      – Definition, Features 
2. What is Sulphate of Potash
      – Definition, Features 
3. Similarities Between Muriate of Potash and Sulphate of Potash
      – Outline of Common Features
4. Difference Between Muriate of Potash and Sulphate of Potash
      – Comparison of Key Differences
5. FAQ: Muriate of Potash and Sulphate of Potash
      – Answers to Frequently Asked Questions

Key Terms

Muriate of Potash, Sulphate of Potash, MOP, SOP, Potassium Chloride, Potassium Sulphate

What is Muriate of Potash (MOP)

Muriate of potash (MOP) or potassium chloride (KCl) is a frequently used fertilizer in agriculture. MOP is derived from naturally occurring mineral deposits, mainly formed from the evaporation of ancient seabed. This fertilizer is extracted, processed and granulated to form the final product, pink or white crystals.

Muriate of potash forms by an ionic bond due to the electrostatic attraction between the two ions, K+and Cl-. Potassium chloride crystallizes in a cubic structure. In this structure, each potassium ion is surrounded by six chloride ions, and vice versa. Electrostatic attraction is maximized due to this specific arrangement in the crystal lattice making it very stable.

Potassium, the main component of MOP, is required for several plant functions. It is involved in the regulation of water balance, strengthening of plant stems, enhancing resistance, and photosynthesis. It is also used in potassium supplementation and certain industrial applications, such as the production of chemicals.

What is Sulphate of Potash (SOP)

Sulphate of potash is also known as potassium sulphate. Its chemical formula is K₂SO₄. This is a white crystalline solid. This is an inorganic compound containing potassium cations and sulphate anions. It is formed through an ionic bond due to the electrostatic attraction between the two ions.

Potassium sulfate crystallizes in an orthorhombic crystal system. This structure has three unequal axes at right angles to each other. Potassium sulfate is highly soluble in water, so plants easily absorb it. This fertilizer typically forms by combining potassium chloride with sulfuric acid. 

This fertilizer is mainly used as a crop fertilizer. It is ideal for crops susceptible to chloride toxicity, such as potatoes, grapes, tobacco, and citrus fruits. It improves crop quality such as fruit taste, colour, size, and increase crop yields.

Similarities Between Muriate of Potash and Sulphate of Potash

1. Muriate of potash and sulphate of potash are potassium fertilizers.
2. Both are highly soluble in water.
3. These fertilizers play a major role in various plant processes.
4. Both can enhance crop yield, quality, and overall plant health.

Difference Between Muriate of Potash and Sulphate of Potash

Definition

• Muriate of potash is potassium chloride (KCl), while sulphate of potash is potassium sulfate (K₂SO₄).

Additional Element

• MOP contains chloride as an additional element, while SOP contains sulfur as an additional element.

Chloride Content

• Muriate of potash has a high chloride content, whereas sulphate of potash is chloride-free.

Cost

• Muriate of potash is generally less expensive than sulphate of potash. 

Conclusion

Potassium fertilizers improve plant health. Muriate of potash and sulphate of potash are two types of such fertilizer. The main difference between muriate of potash and sulphate of potash is their composition. The additional nutrient of muriate of potash is chlorine whereas that of sulphate of potash is sulfur.

FAQ: Muriate of Potash and Sulphate of Potash

1. What is muriate of potash good for?

Muriate of potash, or potassium chloride, is a fertilizer that improves plant health. It strengthens stems, enhances disease resistance, and improves fruit quality.

2. What is the difference between muriate and sulfate?

Muriate and sulfate are both potassium fertilizers. Muriate is cheaper but can build up harmful chloride levels in soil. Sulfate is more expensive but safer, providing sulfur and avoiding chloride buildup.

3. What is sulfate of potash used for?

Sulfate of potash, or potassium sulfate, is a fertilizer that provides potassium and sulfur to plants. It improves fruit development, flower color, and overall plant health.

4. Can muriate of potash be dissolved in water?

Yes, muriate of potash (potassium chloride) readily dissolves in water. Hence, it is used as a fertilizer that plants can absorb easily.

5. When to apply sulphate of potash?

You should apply sulphate of potash during active plant growth for best results, usually in the spring and in summer. This is when plants are producing flowers, fruits, or roots. Sulphate of potash improves flowering, fruiting, and overall plant health.

Reference:

1. “Potassium Chloride.” Wikipedia. Wikipedia Foundation. 
2. “Potassium Sulfate.” Wikipedia. Wikipedia Foundation. 

Image Courtesy:

1. “Compacted potassium chloride, fertilizer grade” By Abbas cucaniensis – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Síran draselný” By Ondřej Mangl – Own work (Public Domain) via Commons Wikimedia