Mono-ammonium phosphate (MAP) is a colorless crystalline solid with a pungent odor at room temperature. MAP is soluble in water, easily soluble in acid, and insoluble in organic solvents. It will deliquescence in the air and become ammonia and phosphate containing several different oxidation levels. MAP is a weakly acidic salt that can react with bases.

Ammonium dihydrogen phosphate (DAP) is an inorganic compound and one of the common salt compounds. Its physical properties are manifested as colorless crystals or crystalline powders, soluble in water and slightly soluble in alcohol.

Ammonium dihydrogen phosphate has a wide range of applications in the agricultural field. It serves as a nitrogen and phosphorus fertilizer, providing crops with the necessary nitrogen and phosphorus nutrients, promoting plant growth, and improving yield and quality. Ammonium dihydrogen phosphate can also be used to prevent and treat phosphorus deficiency in soil, and can improve soil texture and fertility.

There are generally two methods for preparing diammonium hydrogen phosphate. One is obtained by reacting phosphoric acid with ammonia solution, which is a commonly used method in industrial preparation; Another method is to prepare it through the reaction of phosphoric acid and ammonia gas.