Irrigation New Zealand

Fertigation is the term used when using an irrigation systems to apply fertilisers. Fertigation can be a significant advantage over conventional broadcast methods as timing, quantity and accuracy of application can be greatly improved. Generally an irrigation system with fertigation must be managed differently than conventional irrigation and uniformity of application is critical.

The Fertigation resource book, which can be found on the right hand side of this page, will help irrigators that are wanting to install or operating with fertigation. It explains the advantages and disadvantages of different fertigation system types and their componentry. Key operating considerations, including how to calculate application rates are also covered.


INZ has produced an industry good practice guideline for the safe management of irrigation systems that have effluent, fertiliser and/or agrichemical injection (fertigation).

The Guideline for the Safe Management of Irrigation Systems with Effluent, Fertiliser and/or Agrichemical Injection can be found on the right hand-side of this page.

This guideline is intended for designers and installers of irrigation systems with effluent, fertiliser and agrichemical injection. This may include engineers, equipment suppliers, and specialist irrigation designers. The design, installation and testing processes described in this guideline are intended to be applied to agricultural irrigation systems. The guidelines do not amend or replace other industry performance indicators, guidelines, codes of practice or standards. Designers and installers should interpret the guideline according to the requirements of individual properties and owners. All decisions made must also comply with statutes, regulations, and other legal requirements and industry standard

The guideline covers safe management practices and more specifically the recommended safety devices and systems to be used when injecting effluent, fertilisers, herbicides, pesticides and other agrichemicals into irrigation systems. It has been adapted from ASABE 409.1 MAR 1989 R2009. The guideline is not intended to replace backflow protection device recommendations for irrigation systems connected to a sanitary system in NZ. AS/NZS 2845 (2010) is the applicable standard for these scenarios. For irrigation systems where the water source is also used for rural drinking water the NZ Drinking Water standards may apply and impose conditions relating to hazards management.

Environment Canterbury have put together a guide to provide irrigators in the Canterbury region with information on chemigation valves for backflow prevention: Canterbury Backflow prevention Guidelines

You can also visit this page on their website: click here

2019-2021: SFF 405913 Fertigation – a new tool for nutrient management?

In 2019 IrrigationNZ received a grant from the Sustainable Farming Fund to further research the potential benefits of fertigation. Field trials were conducted over two seasons 2019/2020 and 2020/2021 with the aim to further understand whether the use of liquid/dissolved urea through fertigation could increase N use efficiency and pasture production, quality and clover content over traditional solid urea. The project outcomes hope to provide irrigators with clear information for successful fertigation, including providing advice on how to successfully design, install, and manage fertigation systems.

To date the following has been completed:

  • Literary review and key issues identified
  • Year one trials complete and master’s thesis “Can Fertigation Increase Nitrogen Use Efficiency in New Zealand Dairy Pastures?” complete
  • Summary of year 1 findings complete
  • Year two trials were completed in April 2021, results are currently being compiled

Information and reports will continue to be updated on this page as the project progresses.

SFF405913 Fertigation in New Zealand Literature Review and Key Issues Report

SFF405913 Year 1 Summary Results Report

SFF405913 T. Ley Masters Thesis, Can Fertigation Increase Nitrogen Use Efficiency in NZ Dairy Pastures?

With thanks to the Ministry of Primary Industries and our project partners Ballance Agri-nutrients, Molloy Agriculture Ltd,  Pamu Farms of New Zealand, Landcare Research and Fertigation Systems.

Fertigation guideline

Backflow prevention guide