This is the granulated form of monoammonium phosphate at a declared total nutrient content of 55 %, meaning nitrogen plus P₂O₅ together reach 55 percentage points. It is a field-application and bulk-blending product rather than a solution product: the granule is engineered to be spread mechanically, to survive handling without breaking down, and to sit alongside urea, ammonium sulfate and potash granules in a physical blend without segregating. Nutrient concentration is deliberately traded against granule integrity and cost relative to the higher 63 % ([CAS?]) tier.
Substance identity
| Field | Value |
|---|---|
| Active compound | Monoammonium phosphate, NH₄H₂PO₄ |
| CAS | 7722-76-1 |
| PubChem CID | 24402 |
| Molar mass | 115.03 g/mol |
| Grade basis | 55 % = N + P₂O₅ combined, not P₂O₅ alone |
Specification
Typical commercial range — the declared split must be taken from the certificate of analysis:
| Parameter | Typical |
|---|---|
| Total nutrient (N + P₂O₅) | ≥ 55 % |
| Nitrogen (N), ammoniacal | ≈ 10 – 11 % |
| Phosphorus pentoxide (P₂O₅), total | ≈ 44 – 45 % |
| Water-soluble P₂O₅ as % of total | typically ≥ 80 %; declare on CoA |
| Moisture | ≤ 2.0 – 2.5 % |
| Particle size | ≥ 90 % within 2 – 4 mm |
| Bulk density | ≈ 0.9 – 1.1 t/m³ |
| Appearance | grey, brown or off-white granules |
Properties
The chemistry is that of monoammonium phosphate — mildly acidic in solution (1 % solution around pH 4.0–4.5), fully described on the MAP product page. What distinguishes this listing is physical form. Granulation gives:
- Spreadability. A narrow 2–4 mm size distribution and a rounded granule allow centrifugal and pneumatic spreaders to hold a predictable spread pattern across the boom width.
- Blend compatibility. Physical blends segregate during handling when component particle sizes differ. A 2–4 mm MAP granule matches standard granular urea and standard-grade potassium chloride reasonably well; it does not match prilled urea or fine-grade potash, and a blend built across mismatched sizes will separate in the hopper and produce striped fields.
- Crush strength and dust. Granular product resists degradation to fines under conveyor and bag handling; the finer the product breaks down, the worse the spread pattern and the higher the dust exposure.
- Non-hygroscopic in storage relative to urea and ammonium nitrate, though this advantage is partly lost once blended.
Applications
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Basal and pre-plant phosphorus on cereals, maize, cotton, sugarcane and pasture, broadcast and incorporated or drilled.
-
Band placement at sowing, where the acid reaction zone maintains phosphate solubility long enough for young roots to intercept it. Particularly relevant on calcareous and alkaline soils.
- Bulk blend component, supplying the P leg while urea or ammonium sulfate supplies the balance of N and potassium chloride or sulfate supplies K.
- Where 55 % rather than 63 % is the right choice: on programs where phosphate is applied at moderate rates over large areas and freight cost per unit of nutrient is not the binding constraint, or where the higher-analysis grade is not locally available. On long freight legs, the higher-analysis tier delivers the same P₂O₅ in less tonnage and is usually the better economics.
Handling and storage
Store bagged or in bulk under cover, on pallets, in a dry ventilated building. Limit stack height to avoid consolidation caking at the base of the pile. Handle to minimize granule breakage — every additional transfer point generates fines. Do not store or blend with lime, basic slag or other alkaline materials; ammonia is liberated and phosphate availability falls. Keep separate from strong acids. Sweep and dispose of spillage rather than washing to drain.
Notes
-
55 % is a total-nutrient designation. It does not mean 55 % P₂O₅; no granular MAP carries 55 % P₂O₅.
-
Water-soluble P₂O₅ as a percentage of total P₂O₅ is the more agronomically meaningful figure than total P₂O₅ alone, and should be requested explicitly.
- This grade is a soil-applied product. It is not intended for drip irrigation or foliar solutions.