Urea 46-0-0
What it is, how prilled differs from granular, and what a cargo buyer should check before the stem is fixed.
What is urea?
Urea is a solid nitrogen fertilizer with the chemical formula CO(NH₂)₂. It is manufactured by reacting ammonia with carbon dioxide under heat and pressure, then finishing the melt as prills or granules. Fertilizer-grade urea typically assays 46% nitrogen by weight — the highest nitrogen concentration of any commonly traded solid fertilizer.
In trade terms it is written 46-0-0: 46% N, no phosphate, no potash. One tonne of urea therefore carries about 460 kg of nitrogen. That density is why urea dominates global nitrogen cargoes: less freight per unit of nutrient than ammonium sulphate, CAN or AN.
Urea itself is not immediately plant-available. In soil, the enzyme urease converts it first to ammonium and then, through nitrification, to nitrate. Timing, incorporation and moisture decide how much of that nitrogen the crop actually uses — and how much is lost as ammonia gas.
Why buyers care about physical form
Nitrogen content is the same in both forms. What changes is particle size, hardness, dust, caking, dissolution speed and how the cargo survives a voyage, a warehouse and a spreader. Those physical properties decide landed cost more often than the headline FOB number.
Prilled urea
Molten urea is sprayed from the top of a prilling tower. Droplets fall through rising cool air and solidify as small, fairly uniform spheres. Typical size is 0.85–2.8 mm (often quoted 1–2.4 mm). Prills are softer, dissolve faster and usually cost a little less per tonne. They generate more dust, cake more readily in humidity, and are less ideal for wide mechanical spreading or long bulk storage.
Best fit: dissolution (fertigation, liquid blends), hand or small-equipment topdressing, cost-sensitive stems where voyage and warehouse conditions are dry and short.
Granular urea
Urea melt is layered onto seed particles in a drum or fluidised-bed granulator. Formaldehyde is commonly added as a binder. Typical size is 2.0–4.75 mm. Granules are harder (often several times the crush strength of prills), denser, lower-dust and more resistant to caking. Dissolution is slower. Price is typically a few dollars per tonne above prilled.
Best fit: bulk export, humid discharge climates, NPK blending (size match with DAP/MOP), mechanical and pneumatic spreaders, longer warehouse dwell.
Prilled vs granular — buyer snapshot
| Check | Prilled | Granular |
| Typical size | 0.85–2.8 mm | 2.0–4.75 mm |
| Shape | Small smooth spheres | Larger, denser granules |
| Crush strength | Lower — more fragile | Higher — travel-tolerant |
| Dust / fines | Higher | Lower |
| Caking risk | Higher in humidity | Lower if conditioned |
| Dissolve speed | Faster | Slower / more gradual |
| Spreader / blend | Fair; more drift | Preferred for BB and wide throw |
| Usual trade use | Local / dissolve / price-led | Export, bulk, blending plants |
Specification a cargo buyer should lock
Final numbers are confirmed on each stem. The table below is the agricultural export band most counterparties already recognise (aligned with common ISO methods and GB/T 2440-2017 agricultural grade). Always write the test method into the contract.
| Parameter | Typical limit | Why it matters |
| Total nitrogen (N) | 46.0% min | Pay for nutrient, not water or filler. |
| Biuret | 1.0% max | Phytotoxic if high. Foliar / sensitive crops often need ≤0.5–0.9%. |
| Moisture | 0.5% max (prefer ≤0.3%) | Drives caking on the voyage and in the shed. |
| Particle size — prilled | 0.85–2.80 mm, ≥90% | Confirm the exact sieve band on the CoA. |
| Particle size — granular | 2.00–4.75 mm, ≥90–93% | Needed for blending and even spread. |
| Free ammonia | ~160 ppm max | Odour, handling and some industrial specs. |
| Formaldehyde (if treated) | As agreed (often ≤0.6%) | Strength and anti-caking on granular grades. |
| Appearance | White / off-white, free-flowing | Reject visible lumps, discoloration, foreign matter. |
| HS code | 3102.10 | Standard heading for urea, whether or not in aqueous solution. |
Industrial / technical urea is a tighter spec (higher N, lower biuret and moisture, plus iron, alkalinity and insolubles). Do not mix fertilizer and industrial grades on the same contract language.
How to buy without surprises
- Write form on the recap: prilled or granular — not “urea 46%” alone.
- Lock N, biuret, moisture, size band and test methods. Ask for a recent mill CoA before nomination.
- Agree inspection: SGS / BV / Intertek at load, buyer’s cost or 50/50 as negotiated. Sampling plan matters more than the logo.
- Packing: 50 kg PP bags with PE liner, or 1 MT jumbo bags, or bulk. Bulk needs a clean, dry hold and anti-caking discipline.
- Conditioning: confirm whether formaldehyde or other anti-caking treatment is applied — material for humid discharge.
- Incoterms: FOB load port or CIF/CFR discharge. Lot size in this market is commonly 10–25 kt for vessel stems.
- Storage after arrival: covered, dry, RH preferably under 60%, pallets off the floor, limited stack height. Use promptly; urea is hygroscopic.
- Application reminder for the end-user: incorporate or irrigate after surface application where possible. Bare urea on a hot, windy soil surface loses nitrogen as ammonia.
What this product is — and is not — at Ametheus
Ametheus supplies urea as a structural fertilizer cargo to industrial buyers, blenders and trade partners. Execution is FOB load port or CIF/CFR discharge. Typical lot 10–25 kt. This is international / STE-tender style supply — not farm-gate 50 kg retail, not an open-market Indian agricultural import offer, and not an MRP bag competing with domestic co-operatives.
India urea stems, where applicable, are international or STE-tender supply only. Final specification is confirmed on each stem.
Quick decision guide
- Need fast dissolve or lowest unit price and short, dry logistics → prilled.
- Need export durability, blending, mechanical spreading or humid storage → granular.
- Need foliar or sensitive-crop use → specify low biuret, not only 46% N.
- Need industrial resin / technical use → do not buy fertilizer-grade language.
Ametheus Holdings Pvt Ltd
Communication: Vaswani Chambers, 1st Floor, 264-265 Dr. Annie Besant Road, Worli, Mumbai 400025, India. Email: [email protected] · www.ametheus.com
This briefing is for counterparties evaluating a urea cargo. It is not a farm-gate recommendation, not a price indication, and not an offer. Specification, origin, packing and inspection are as agreed in the contract.
