Monopotassium Phosphate, MKP, (also potassium dihydrogenphosphate, PPK, or monobasic potassium phosphate), KH2PO4, are potassium-soluble salts and dihydrogen phosphate ions used as fertilizers, food additives and fungicides. It is a source of phosphorus and potassium. It is also a buffer agent. When used in a mixture of fertilizer with urea and ammonium phosphate, it minimizes ammonia runaway by keeping the pH at a relatively low level.