Sulphate of Potash (SOP) is an inorganic compound with formula K2SO4. SOP is a white water-soluble solid that is commonly used in higher value fertilizers, providing both potassium and a source of sulphur. Its high potassium content makes it ideal for encouraging strong plant development, particularly for fruits and vegetables. It also helps to ripen and strengthen plants ensuring they can defend against pest, disease and weather damage. Globally some 2 million tonnes of SOP is consumed each year.