With crops at the site starting to progress with some timely rainfall in June and July, the team at SFS have begun applying the first timing of Urea applications to trials. Nitrogen is a key factor in maximising plant growth and yield potential of crops; however, previous research has shown that there can be a significant portion of applied N lost from the cropping system when best management practices are not applied. This not only comes at a cost to the profitability of your crop but also can significantly increase your greenhouse gas emissions on farm through Nitrous Oxide losses.

One avenue for improving your Nitrogen Use Efficiency (NUE) on farm is through selecting the ‘Right Product’.  Right Product refers to the different forms of N fertilisers such as granular urea, coated urea and liquid N fertilisers. Typically, in the high rainfall zone (HRZ), uncoated granular urea is the most used product. When applied at the wrong timing or under unfavourable conditions, uncoated granular urea can result in significant losses. Products such as coated nitrogen and liquid urea have proven to reduce losses, improve NUE and environmental impacts.

Using treated nitrogen fertilisers can help you get more value from your nitrogen while reducing losses to the environment. There are three main types to consider:

•  Nitrification inhibitors slow down the conversion of ammonium to nitrate in the soil, which helps keep nitrogen available for longer and can cut nitrous oxide (N₂O) emissions by up to 80%.
• Urease inhibitors, like those found in green urea, prevent the rapid release of ammonia gas, reducing nitrogen loss through volatilisation.
• Lastly, coated and controlled-release fertilisers use special coatings (like polymers or oils) to release nitrogen gradually, so it’s available to crops over time rather than all at once. While these products can reduce nitrogen losses and improve efficiency, the boost in crop yield is often modest—so financial support or incentives from a emissions reduction perspective, may be needed to make them a practical choice on-farm.

Liquid Nitrogen can be absorbed quickly by plant leaves and roots when applied directly to the leaf and/or soil. This allows the nitrogen to be readily available when applied and matching that with periods of high N demand in the crop will improve the NUE and reduce losses from leaching, run-off and volatilisation.

Image: Ute spreader applying first urea applications. Source: J Palmer, SFS