Sulphate of Potash (S.O.P)
- SOP provides both potassium and sulphur in soluble forms.
- SOP contains no chloride and hence has a much lower salt index than MOP. Where soils are saline or sodic and where irrigation water may have high chloride levels SOP is the preferred form of potassium to use.
- Where seeds or transplants are placed in direct contact with fertiliser, SOP is much less likely to cause root burn of plants.
- Potassium stimulates the growth of strong stems and gives the plant some disease resistance by promoting thickness of the outer cell walls. Adequate potassium can reduce moisture loss from growing plants, thereby giving some drought resistance. Potassium improves colour, flavour and storing quality of fruit and vegetables.
Potassium sulphate (SOP) can be used where ever MOP is used however it is incredibly valuable in the following areas:
- Where soil or irrigation water salt levels are high and MOP is undesirable.
- Where chloride sensitive crops are being grown; for example, berries and vines.
- Where high chloride levels occur in irrigation water.