Image: University of Canterbury senior lecturer in physical chemistry? Dr Deborah Crittenden

As many people who live in the Land of the Long White Cloud know, over-production and distribution of nutrients such as nitrates and phosphates due to dairying and crop production is a serious problem in New Zealand. A by-product of intensive agriculture and farming practices, high nitrate levels in water and soil are harmful to the environment – and to human health.

UC scientists Dr Deborah Crittenden (a senior lecturer in physical chemistry and an associate investigator in the Biomolecular Interaction Centre) and environmental chemistry associate professor Sally Gaw (a member of the Waterways Centre for Freshwater Management) know all about this – and they’re collaborating to develop a laser sensor capable of measuring nitrates in the field.

The tool is currently at the lab development stage, but winning $20,000 from UC’s annual Tech Jumpstart competition and a further $35,000 from Astrolab – a business incubator providing commercialisation expertise – will help to transform their project into commercial reality.

The sensor promises to be portable (and it may eventually be able to be used by a drone) and cost-effective with a low-environmental impact. It will be capable of selecting only nitrates from a soil sample, avoiding other deposits or substances with similar structures. Crittenden says this type of tool has never been tried or even proposed before in the context of developing nitrate sensors – and as such requires the development of new technologies because existing sampling is performed using lab-based methods.

University of Canterbury environmental chemistry associate professor Sally Gaw.

So… is it feasible? Crittenden certainly thinks so. “With the introduction of new legislative caps on nitrogen discharge, a portable nitrate measuring tool would enable farmers to conveniently measure nitrate levels on the farm, helping them to keep discharges within the new limits,” she explains. “Better monitoring of nutrient levels will enable more effective interventions to prevent further environmental damage.”

And that damage needs to be stopped – or at least slowed – before it’s too late, Crittenden adds. “Similarly, levels of phosphate in waterways are also increasing due to over-use of fertilisers, leading to outbreaks of algal blooms and making water unfit for drinking and swimming. There is therefore an urgent need to monitor nutrient levels in the field in real-time.”

To help with their research, the scientists are recruiting a master’s student to work on the project. Students interested in applying can contact Crittenden or Gaw directly.

In the meantime, we’re crossing our fingers this idea becomes a reality in order to help save the planet.