What is the problem?

Over application of nitrogen fertiliser is expensive, inefficient and run-off containing nitrogen can end up polluting waterways.

What was the purpose of the trial?

In 2017 Living Water commissioned a demonstration project on the fine particle application of fertiliser in the Waituna catchment. The project assessed the effects of applying nitrogenous fertiliser (urea) using a fine particle application (FPA) method compared to conventional application of granular fertiliser. The FPA system uses precisely the same fertiliser as used in any granular fertiliser application. The difference however, arises from the way the product is applied. The granular fertiliser is ground up into a fine particle size (less than 1mm), that is distributed more evenly over the pasture achieving a better overall distribution pattern across the paddock.

Previous studies suggest that FPA may achieve a similar pasture response to conventional application using less fertiliser and could result in greater fertiliser efficiency, reduced costs and potentially a reduction in nitrogen loss to water. Living Water was interested to see if nitrogen fertiliser application use can be reduced without compromising pasture growth.

Who could use fine particle application of fertilisers?

Landowners, farmers, farm and land managers.

How was the project undertaken?

The project had three main components:

1. A review of FPA literature, which was completed in September 2017; Literature review critiqueby Jeff Morton, Morton Ag, in March 2018; and an Independent peer review by AgResearch of the literature review and demonstration method completed in June 2018.
2. An on-farm demonstration site that compares conventional fertiliser application with FPA, was established in March 2017, with the first cut and weigh in April 2017. Twelve further cut and weigh exercises were conducted, with the last in June 2018.
3. Sharing the findings of the literature review and demonstration plots with farmers took place at field days held in Oct 2017, Feb 2018 and Jul 2018

The Final report and presentation of the demonstration project was completed in July 2018.

AgResearch have completed a review of the data of 250 FPA demonstration plots from around New Zealand where data has been gathered over multiple years in exactly the same way as the Waituna demonstration.

What did Living Water learn from the trial?

The trial demonstrated that by using the fine particle application system, 30kgs of Urea produces the same quantity of pasture dry matter as 60kgs of Urea applied in a conventional granular application.

Use of the fine particle application system provides significant benefits at the farm system level. These include:

• Greater dispersion of nitrogen through the soil, providing access to a larger root surface area
• Faster uptake of nitrogen resulting in lower losses of ammonia and nitrous oxide gases
• Plants get nutrients enabling faster growth rates and more Dry Matter (DM) pasture growth
• Improved pasture growth rates lead to increased farm productivity and financial gains

Fonterra Farm Source is investigating the feasibility of scaling the FPA approach.

Where is more information available about fine particle application?

Visit the FPA website