Potash is the common name given to a group of potassium-bearing minerals various mined and manufactured salts that contain the potassium. The historical term potash arose from the traditional practice of producing potassium carbonate, needed for making soap, by the leaching of wood ashes in large iron pots. The ash-like crystalline residue remaining in the large iron pots was called "pot ash".
Approximately one-third of annual global potash production capacity is located in Canada, making it the leading world producer. Canada controls about half of the world's proven and probable potash resources. Potash mining infrastructure is currently available in Saskatchewan due to the operation of a large number of potash mines.
Approximately 95% of world potash production is used for agricultural fertilizer (Saskatchewan Mining Association). Fertilizers replace the nutrients that crops remove from the soil, thereby sustaining or enhancing the yield of crops. Plants deficient in potassium are less resistant to pests and disease, and have poor size, shape, colour, taste and shelf life. The functions potassium performs cannot be carried out by other nutrients and potash has no commercially viable substitute as a potassium fertilizer source. The remaining potash consumption is made up of the manufacture of potassium bearing chemicals, detergents, ceramics and pharmaceuticals, as well as water conditioner and de-icing salt.
A key factor that has led to the steady increase in fertilizer consumption over the past 50 years is the need to produce increasing amounts of food from shrinking amounts of arable land per capita. Global demand for potash is expected to grow at a rate of 3% per year through 2016 (USGS 2011 Minerals Yearbook).