Author: Reily Menhenett, Incitec Pivot Technical Agronomist – Broadacre, Agronomy & Ideation 

Nitrogen efficiency underpins yield, return on investment, and the long-term performance and resilience of a farming system. Urea, the most globally important nitrogen (N) fertiliser, has many logistical benefits due to its high analysis and ease of application. However, if surface applied under unfavourable conditions, a significant proportion of that N can be lost before it becomes available to the crop. 

To combat this, Incitec Pivot Smart Fertiliser Green Urea NV® is designed to reduce nitrogen losses by slowing ammonia volatilisation and keeping nitrogen in the paddock. 

The volatilisation pathway 

Once urea is applied to a moist soil surface, it’s quickly broken down by the naturally occurring urease enzyme, typically within 1-4 days This process (Figure 1) – known as urea hydrolysis – converts urea into ammonium, via the unstable intermediate, ammonium carbonate. 

Figure 1: The urea hydrolysis process. Source: Incitec Pivot, 2026 

Without timely rainfall or irrigation, ammonium carbonate remains at the soil surface. Until it is incorporated, nitrogen is lost to the atmosphere as ammonia gas. Field trials have shown that up to one-third of applied nitrogen can be lost this way when urea remains at the soil surface, unprotected.  

How Green Urea NV works: slowing the reaction 

Green Urea NV contains NBPT (N-(n-butyl) thiophosphoric triamide), the most widely researched and globally adopted urease inhibitor. It is a coating that penetrates the urea granule rather than sitting on the surface. 

NBPT works by temporarily inhibiting urease activity in the soil, binding the nickel ions required to catalyse the reaction (Figure 2). This delays the hydrolysis of urea for up to 14 days, prolonging the window for an effective incorporation event.  

Figure 2: Role of Green Urea NV in reducing volatilisation losses during the urea hydrolysis process. Source: Incitec Pivot, 2026. 

In practical terms, this means: 

  • More time for rainfall or irrigation to move nitrogen into the soil. 
  • Less ammonia volatilisation from surface-applied urea. 
  • A higher proportion of applied nitrogen remaining plant-available. 

It’s a biochemical delay, not a physical barrier – after 14 days, the NBPT will start to wear off, allowing the nitrogen cycle to continue.  

Further information 

If you would like to learn more about Green Urea NV, how it works and where it can fit into your farm business, contact Incitec Pivot Technical Agronomist, Reily Menhenett on 0474093167 or at reily.menhenett@incitecpivot.com.au.