DAP and MAP: Characteristics
Nutrient grade, granule strength and cadmium
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.DAP and MAP are sold on guaranteed nutrient grades and granule quality. Buyers care about N and P2O5 content, water solubility of the phosphate, moisture and granule strength (to survive handling) and heavy metals such as cadmium. Colour varies with rock source and has no agronomic effect.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Nutrient grade | DAP 18% N, 46% P2O5; MAP 11% N, 52% P2O5 | price is per tonne at grade; subsidy is per kg nutrient | Fertiliser (Control) Order 1985; standard grades |
| Water-soluble P2O5 | DAP at least 41% water-soluble P2O5 under India's FCO (indicative) | only soluble P is quickly available to crops | Fertiliser (Control) Order (indicative) |
| Moisture | at most 1.5-2.5% by weight (indicative) | moist granules cake | FCO; industry practice (indicative) |
| Granule size | 90% between 1 and 4 mm (indicative) | even spreading and blending | industry practice (indicative) |
| Cadmium | EU limit 60 mg Cd/kg P2O5 | sets premium for igneous rock products | EU 2019/1009 |
Commercial grades
- DAP 18-46-0 (granular, standard)
- MAP 11-52-0 (granular, for blends and Brazil)
- APS 20-20-0-13 (India)
- Technical MAP 12-61-0 (fertigation, fire retardants)