Potassium Carbonate is also known as Potash Carbonate. It is used worldwide as a major source for Potassium in fertilizer. A higher level of Potassium helps in fruit developmentâ Potassium carbonateâ is the inorganic compound with the formula K2CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing as a damp or wet solid.