This fact sheet outlines the differences between urea, urease inhibitors, polymer coated urea (PCU), nitrification inhibitors, calcined ammonium nitrate, ammonium sulphate or sulphate of ammonia and compound fertilisers.
Key points
Urea is the cheapest and most common form of fertiliser N but it is also most prone to loss through volatilisation (loss as ammonia gas).
Urea is best used when incorporated or banded into the soil.
Urea with urease inhibitors can reduce volatilisation when surface broadcast, thus providing more flexibility regarding timing and can improve fertiliser utilisation over standard urea for a relatively low additional cost.
Other nitrogen fertilisers such as Ammonium sulphate or sulphate of ammonia (SOA), calcium ammonium nitrate (CAN) or polymer coated urea (PCU) are more expensive.
Compound fertilisers are typically used at planting and supply only some of the fertiliser nitrogen required by the crop.