Diammonium phosphate (DAP) is the world’s most widely used phosphorus (P) fertilizer. It is made from two common constituents in the fertilizer industry and it is popular because of its relatively high nutrient content and its excellent physical properties. Production Ammonium phosphate fertilizers first became available in the 1960s and DAP rapidly became the most popular in this class of products. It is formulated in a controlled reaction of phosphoric acid with ammonia, where the hot slurry is then cooled, granulated, and sieved. DAP has excellent handling and storage properties.
The standard grade of DAP is 18-46-0 and fertilizer products with a lower nutrient content may not be labeled as DAP. The inputs required to produce one ton of DAP fertilizer are approximately 1.5 to 2 tons of phosphate rock, 0.4 tons of sulfur (S), to dissolve the rock, and 0.2 tons of ammonia. Changes in the supply or price of any of these inputs will impact DAP prices and availability. The high nutrient content of DAP is helpful in reducing handling, freight, and application costs. DAP is produced in many locations in the world and is a widely traded fertilizer commodity