About SOP - Overview

Potash is a generic term that refers to a group of potassium-bearing minerals, naturally occurring potassium salts and the products produced from those salts.

Potash is a plant's main source of potassium. Potassium ("K") is one of the four primary nutrients required for plant growth. The remaining three nutrients are Nitrogen ("N"), Phosphate ("P") and Sulphur ("S"). Potash is used in fertilizers and applied through the soil for uptake by plant roots.


Suphate of Potash (SOP) Muriate of Potash (MOP)
Potassium Sulphate (K2SO4) Potassium Chloride (KCI)
  • 6 million tonnes sold in 2011
  • 55.7 million tonnes sold in 2011
  • Potassium and sulphur are essential nutrients
  • Crop quality/yield diminish as chloride builds up
  • Improves yield, quantity, taste and enhances shelf life

Muriate of Potash (MOP) which is also known as Potassium Chloride (KCI) is widely used in all types of farming but contains a chloride ion that can be detrimental towards plant growth, especially fruits and vegetables. If the chloride content isn't managed, it can lead to low quality crops and inhibit place growth in dry soils and saline areas. MOP is the most commonly used and has a global market size of approximately 55 million tonnes/year.


Chloride Tolerance of Various Crops
Tolerance Crop Type Recommended Product
Chloride-loving Sugar beet, fodder beet, celery, Swiss chard, coconut Muriate of Potash (MOP)
Chloride tolerant
Cereals, maize, oilseed rape, asparagus, cabbage, beetroot, rhubard Grassland, clover, oil palm, rubber, rice, groundnut, cassava, soybean, sugar cane, banana, cotton Muriate of Potash (MOP)
Partly chloride tolerant Sunflowers, grape vines, stone fruits, blackcurrants, seed potatoes, potatoes for human consumption, tomatoes, radish, kohirabi, peas, spinach, carrots, leek, horse-radish, chicory, pineapple, cucumber, kiwifruit, cofee, tea Sulphate of Potash (SOP)
Chloride sensitive Starch potatoes, potatoes for processing, tobacco, redcurrants, gooseberry, raspberry, strawberry, blackberry, blueberry, mango, citrus, pepper, chilli, avocado, cashew, almond, peach, cocoa, hops, pomes and stone fruits (especialy cherries), bush beans, broad beans, cucumber, melon, onion, lettuce, early vegetables, all crops under glass, conifers, flowers and ornaments as well as seedlings and transplants of most plants Sulphate of Potash (SOP)

Source: K&S Kali GmbH