New tool could reduce fertiliser use and clean up waterways

A break-through testing device for phosphates could help farmers and deliver cleaner waterways for everyone.

  • Deborah Crittenden

    University of Canterbury Associate Professor of Physical and Chemical Sciences Deborah Crittenden says farmers want and need a user-friendly device that will allow them to accurately test for phosphates.

SDG 12

Sustainable Development Goal (SDG) 12 – Sustainable consumption and production.

Te Whare Wānanga o Waitaha | University of Canterbury (UC) Associate Professor of Physical and Chemical Sciences Deborah Crittenden says farmers want and need a user-friendly device that will allow them to accurately test for phosphates, a compound formed when fertiliser run-off gets into waterways.

“Phosphates can cause damaging algal blooms, but we want to provide farmers with real-time, accurate test kits that will allow them to better monitor and control fertiliser use on their land, with test results sent instantly to their computer or phone.

“Recent nutrient management laws introduced by the Government require them to pay if they are predicted to breach certain levels of fertiliser run-off in waterways, and the advice we’ve received from farmers is that there is strong demand for a tool that accurately measures actual phosphate levels in waterways,” she says. “That’s exactly what we’re planning to deliver.”

Associate Professor Crittenden says currently there isn’t a simple, chemical-free way of monitoring phosphate levels. “Phosphate is a very tricky compound to detect – it’s odourless and colourless, both to the naked eye and to sophisticated instruments. But we’ve already developed very sophisticated ways of sensing phosphate in our bodies – so we are going to learn from nature to develop novel light-sensitive biosensors.”

The new devices will be designed to be reusable and contained in an easy-to-use, portable marker-pen size device that can be put into rivers and streams. They could boost Aotearoa New Zealand’s agritech exports and generate up to $8 million a year in export earnings while also cleaning up local waterways, Associate Professor Crittenden says.

The underlying technology could also have applications in medical, industrial and veterinary settings. “The modular design of our bio-nanosensors means that this approach can be extended to detecting other pathogens and environmental contaminants.

“Our end goal is to produce and manufacture our phosphate sensors in Aotearoa New Zealand, creating local jobs and ensuring all of the benefits of our technology are fully realised in Aotearoa New Zealand.”

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