Monopotassium phosphate -- KH2PO4 -- (MKP) is a soluble salt which is used as a fertilizer, a food additive and a fungicide. It is a source of phosphorus and potassium, and is a buffering agent. When used in fertilizer mixtures with urea and ammonium phosphates, it minimizes escape of ammonia by keeping the pH at a relatively low level.
Fertilizer grade MKP contains 52% P2O5 and 34% K2O, and is labeled 0-52-34. It is often used as a nutrient source in the greenhouse trade and in hydroponics.
It is one of the components of Gatorade and is used as an additive in cigarettes.