What is DAP fertilizer?
VBT Global · Published
Short answer: DAP is diammonium phosphate, (NH₄)₂HPO₄. It is a granular fertilizer that supplies nitrogen and phosphorus in water-soluble form. In Vietnam it must contain at least 15 % total nitrogen and 42 % available P₂O₅ by mass (QCVN 106:2025/BNNMT).
What DAP is made of
DAP is made by reacting phosphoric acid with ammonia, then granulating and drying the product. The phosphoric acid in turn comes from phosphate rock. That is why phosphate-mining regions such as Lào Cai province in northern Vietnam are also where phosphate fertilizers are made.
What DAP does for crops
- Phosphorus drives root development, flowering and grain fill, and early-season phosphorus is hard to make up later
- Nitrogen in ammonium form supports early growth
- Because both are water-soluble, they are available to the crop soon after application
How DAP is applied
- Usually as a basal (pre-plant) application, broadcast and incorporated or banded beside the row
- Not in direct contact with seed. The ammonia released as DAP dissolves can injure germinating seeds.
- Works best on neutral to acidic soils. On alkaline soils, MAP is often the better phosphate (see MAP vs DAP).
- Widely used as a phosphorus source in bulk blends and NPK production
Grades and quality
The national regulation sets the minimums (N ≥ 15 %, P₂O₅ ≥ 42 %). Commercial grades, granule size and colour are agreed between buyer and seller and confirmed on the certificate of analysis for each lot. Colour varies with the phosphate rock and process. It is not a quality measure on its own.
Trade details
HS code 3105.30. Shipped in bulk, jumbo bags or 50 kg bags.
Buying DAP for export
VBT Global sources DAP from plants in Lào Cai province and trucks it to the port of loading on its own fleet. We quote bulk export lots to business buyers only, and we do not sell bags to farmers in Vietnam. DAP · Request a quotation