Diammonium phosphate (DAP) is the world’s most widely used phosphorus fertilizer. It’s made from two common constituents in the fertilizer industry, and its relatively high nutrient content and excellent physical properties make it a popular choice in farming and other industrie

It’s formulated in a controlled reaction of phosphoric acid with ammonia, where the hot slurry is then cooled, granulated and sieved. DAP handles and stores well. The standard nutrient grade of DAP is relatively high, at 18-46-0. The high nutrient content of DAP helps reduce handling, freight and application costs. DAP is produced in many locations in the world and is a widely traded fertilizer commodity.

 Chemical properties

Chemical formula: (NH₄)₂HPO₄

Composition: 18% N, 46% P₂O₅ (20% P)

Water solubility (20 degrees C): 588 g/L

Solution pH: 7.5 to 8

 Agricultural use

DAP fertilizer is an excellent source of P and nitrogen (N) for plant nutrition. It’s highly soluble and thus dissolves quickly in soil to release plant-available phosphate and ammonium. A notable property of DAP is the alkaline pH that develops around the dissolving granul…