Urea phosphate is an organic compound of carbon, hydrogen, nitrogen, oxygen and phosphorus. Its formula is CO(NH2)2.H3PO4. It is made by reacting urea with phosphoric acid.
It is sometimes used as a fertilizer; as such, its NPK formula is 17-44-0. It is soluble in water, and produces a strongly acidic solution. Urea phosphate is sometimes added to blends which contain calcium nitrate and magnesium nitrate to produce water-soluble formulas such as 15-5-15, 13-2-20, and 13-2-13. The acidity of urea phosphate allows Ca, Mg and P to co-exist in solution. Under less acidic conditions, there would be precipitation of Ca-Mg phosphates. Urea phosphate is often used in Drip irrigation to clean the pipe system.