Cutting Nitrogen Loss: What We Learned from the Green Urea NV Trials

Nitrogen efficiency has been a talking point for years, and with fertiliser being one of the biggest on-farm investments, every kilo counts. That’s why we teamed up with Incitec Pivot and ran a series of trials looking at how different nitrogen products perform under local conditions.

Incitec Pivot Fertiliser NV Trial Report 2024

Setting Up the Trials

Our team helped establish trial sites in the Longerenong and Hopetoun areas, with additional sites run by co-operators across Victoria and South Australia. Treatments included:

• Standard urea

• Green Urea NV (urease inhibitor)

• Easy N

• Gran Am

The aim was to measure nitrogen volatilisation — essentially, how much N is lost as ammonia gas after spreading.

What We Found in the Field

At Longerenong, we ran three topdress applications throughout the season, applying nitrogen at the equivalent of 100 kg/ha of urea. Measurements showed:

• Standard urea lost around 13% of applied nitrogen within just two weeks

• Green Urea NV lost only 2%

• That’s an 83% reduction in nitrogen loss

These results were consistent across all three topdress timings. Put simply, growers spreading 100 kg of urea were effectively only getting about 73 kg working in the paddock, while Green Urea NV retained closer to the full rate.

Backed by Broader Research

The wider trial program conducted by Incitec Pivot Fertilisers across 11 winter cropping sites confirmed what we saw locally:

• Standard urea lost up to 26% of applied N in some situations

• Green Urea NV consistently cut losses by around 77–82%, depending on timing

• Most of the losses occurred in the first week after spreading

  
  

The Economics

Losing nitrogen isn’t just about wasted fertiliser dollars — it’s lost yield potential. At Longerenong, the cost of volatilisation was estimated at nearly $60/ha for standard urea compared to just $20/ha for Green Urea NV. That’s a positive return of about $40/ha once yield impact is factored in.

Why It Matters

Every season is different, but the message is clear: slowing nitrogen loss means more fertiliser working where it should — in the crop. Products like Green Urea NV give growers another tool to improve efficiency, especially in surface-applied situations where the risk of loss is highest.

Learn More

We’ve pulled together the trial data and product information in our new Resource Hub.👉 Visit the Crop Opti Resource Hub for the full trial reports, technical data, and grower insights.