Future Landscapes
Benign Denitrification in Groundwaters
Developing a cost-effective technique to assess denitrification processes and end products in shallow groundwaters
PROJECT DETAILS
Challenge funding: $170,000
Research duration: January 2017 – December 2018
What Are We Doing?
Denitrification is the natural process of soil bacteria converting nitrate back into atmospheric nitrogen gas. This process could reduce (attenuate) the environmentally damaging impacts of nitrate leached from farms to freshwater.
It is important that the denitrification process is complete, because incomplete denitrification can release nitrous oxide (N2O, a harmful greenhouse gas) rather than dinitrogen (N2, a harmless gas making up 78% of the atmosphere).
Benign Denitrification in Groundwaters research will develop a cost-effective and rapid technique to accurately assess denitrification processes and end products (nitrous oxide and/or dinitrogen) in shallow groundwaters in the Manawatu and Rangitikei river catchments. This cost-effective technique will be used to measure and map complete benign denitrification hotspots across New Zealand’s agricultural catchments.
How Can The Research Be Used?
- The research has found that the capacity of natural denitrification processes to reduce nitrogen varies a great deal spatially, even within the same catchment. Some parts of a catchment may therefore contribute disproportionately to river contamination of nitrogen, while areas with high nitrogen attenuation capacity may be suitable for strategic intensification of land use.
- Researchers in the Benign Denitrification in Groundwaters project are working collaboratively with Horizons Regional Council and Waikato Regional Council, having agreed that the denitrification measurement tools will be used by the Councils.
- The first end users will include Massey University’s Fertilizer and Lime Research Centre (FLRC), Horizons Regional Council, Waikato Regional Council, and Our Land and Water researchers and partners.
In the Media
Autumn 2019 (page 36)
The Massey University-led research analysed the likely result of strategically intensifying land use in more than 83,000ha of high nitrogen attenuation capacity areas in the catchment – while de-intensifying land use over about 10,000ha
VIEW ARTICLE →Dairy Farmer, 18 February 2019
Because the leached nitrogen flowed through aquifers where a lot of denitrification occurred, most of the leached nitrogen was converted to gaseous forms and lost to air. The result was that the load in the river would have likely decreased by 6%
VIEW ARTICLE →TVOne, 2015
“We found that nitrogen reduction capacity varies quite a bit from sub-catchment to sub-catchment,” says Ranvir Singh. “That is very interesting because we did not know that this reduction underground was that variable, and we are not utilising it properly”
VIEW ARTICLE →NZ Geographic, July-August 2017
This capacity to attenuate nitrogen is highly variable across a catchment, Singh said. “This leads you to conclude that some parts of a catchment are contributing disproportionately to river contamination”
VIEW ARTICLE →Team Snapshot
Research Outputs
Conference Papers
CONFERENCE PRESENTATIONS
Have a Question?
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