Diammonium Phosphate (DAP)
Chemical Formula: (NH₄)₂HPO₄, Standard Grade: 18-46-0
Diammonium Phosphate (DAP) is one of the most widely used high-analysis phosphate fertilizers in global agriculture. It supplies two essential macronutrients — Nitrogen (N) and Phosphorus (P₂O₅) — in a highly concentrated, water-soluble form. DAP is produced by the controlled reaction of ammonia (NH₃) with phosphoric acid (H₃PO₄), followed by granulation, drying, and screening.
When applied to soil, DAP rapidly dissolves and releases ammonium (NH₄⁺) and phosphate (H₂PO₄⁻ / HPO₄²⁻) ions that are immediately available for plant uptake. It is particularly valued as a basal / starter fertilizer because of its dual nutrient supply and excellent physical handling properties.
Technical Specifications
| Parameter | Unit | Fertilizer Grade (Standard) | Industry / Technical Grade |
|---|---|---|---|
| Purity | % | — | 99 min |
| Total Nutrient (N + P₂O₅) | % | 64 min | 74 min |
| Total Nitrogen (N) | % | 18 min | 21 min |
| Phosphorus Pentoxide (P₂O₅) | % | 46 min | 53 min |
| Moisture | % | 2.5 max | 0.2 max |
| Water Insoluble | % | 0.1 max | 0.1 max |
| pH (1% solution) | — | 7.8 – 8.2 | 7.8 – 8.2 |
| Particle Size (1–4 mm) | % | 90 min | — |
| Arsenic (As) | ppm | 20 max | 10 max |
| Cadmium (Cd) | ppm | 7 max | 0.5 max |
| Mercury (Hg) | ppm | 0.1 max | 0.1 max |
| Selenium (Se) | ppm | 1 max | 0.1 max |
| Lead (Pb) | ppm | 10 max | 0.001 max |
| Appearance | — | Brown granular | White crystalline powder |
Typical Physical Properties (Fertilizer Grade)
- Bulk density: approximately 900–950 kg/m³
- Granule size: predominantly 2–4 mm
- High water solubility (≈ 588 g/L at 20 °C)
- Free-flowing with good storage and handling characteristics
Key Benefits
- High nutrient concentration — 18% N + 46% P₂O₅ in every granule reduces transport and application costs.
- Immediate nutrient availability — Highly water-soluble; both nitrogen and phosphorus become plant-available soon after application.
- Ammoniacal nitrogen — Resists leaching compared to nitrate forms and supports early vegetative growth.
- Starter fertilizer advantage — Excellent for placement near the seed or transplant to promote strong root development.
- Compatible with most blending operations — Widely used as a base material in NPK compound fertilizers.
- Alkaline reaction zone — Creates a temporary higher pH around the granule, which can improve phosphorus availability in acidic soils.
Recommended Applications
DAP is suitable for a wide range of crops and farming systems:
Cereals & Field Crops Wheat, maize/corn, barley, rice, sugarcane, sugar beet
Oilseeds & Pulses Sunflower, soybean, groundnut, pulses
Vegetables Potato, tomato, onion, cucumber, chilli, leafy vegetables
Fruit & Plantation Crops Apple, pear, citrus, mango, pistachio, banana, oil palm
Other Uses
- Basal dressing before sowing or transplanting
- Starter fertilizer in precision placement systems
- Component in bulk blends and NPK compounds
- Limited use in fertigation after proper dissolution
Typical Application Rates (guide only — actual rates depend on soil test, crop, and region): 100–250 kg/ha as basal dose for most field crops.
Packaging Options
- 50 kg polypropylene bags (most common for retail and medium-scale use)
- 500 kg / 1,000 kg jumbo bags (FIBC)
- Bulk (loose) for large industrial and commercial farms
Storage & Handling Recommendations
- Store in a cool, dry, well-ventilated warehouse protected from moisture and direct sunlight.
- Keep bags sealed and stacked on pallets to prevent caking.
- Avoid contact with alkaline materials.
- Use appropriate personal protective equipment during handling (dust mask, gloves).
Summary
Diammonium Phosphate (18-46-0) remains one of the most efficient and cost-effective sources of nitrogen and phosphorus for modern agriculture. Its high analysis, excellent solubility, and reliable physical properties make it a preferred choice for farmers and fertilizer blenders worldwide.
For commercial inquiries, technical data sheets, or current availability, please contact us.
Contact: +91-9999999538, +91-9999099538 (WA), +91-9999156157 (WA) | Email: [email protected]
