The utilization of real-time water quality monitoring to demonstrate the positive impact of farm management on freshwater quality has become increasingly valuable in recent years. To this end, industry experts The AgriBusiness Group, along with dairy farmers John and Sarah Wright, Nicole Holliday from Balance Agri-Nutrients, and Dr Blair Miller from Lincoln Agritech collaborated to deploy three HydroMetrics GW50PC Nitrate Sensors on the Wright’s dairy farm along the Opihi River near Fairlie, Canterbury. This endeavor measured nitrate spikes by exhibiting actual nitrate concentrations in groundwater as it passed through the farm. Despite real-time sensors requiring an upfront investment, the resultant data, comprising 8,760 hourly readings annually, is comprehensive and dependable. The findings demonstrated the probability of nitrogen (N) spikes aligned with precipitation events, with the upper and lower sites capturing N concentrations in groundwater flow from the top down. Farmers can gain insight from the unforeseen results depicting higher N concentrations over the winter, but extending the findings may prove challenging due to the changing climatic conditions from season to season.
The implementation of real-time nitrate sensors on the farm of John and Sarah Wright has provided valuable insights into the sources and transport pathways of contaminants in agricultural settings. The farm is situated in a region renowned for its natural beauty and has been designated as a High Nitrogen Concentration Zone by Environment Canterbury, with a requirement for farmers in the area to reduce N leaching losses. The sensors have allowed for continuous monitoring of nitrate concentrations, consequently providing high-resolution data for better understanding of how nitrate levels respond to weather and irrigation. Through this system, it is possible to ascertain the immediate effects of such factors on nitrate losses, as well as to develop mitigation strategies to improve water quality. Thus, this initiative has increased knowledge sharing within the community and facilitated collaboration to tackle water quality challenges.
John, a farmer, partnered with agricultural consultant Charlotte Senior to gather baseline data in compliance with potential future regulations surrounding nitrates and groundwater. With the help of real-time sensors, they installed three HydroMetrics GW50PC nitrate sensors along the direction of groundwater flow. Ten farmers expressed interest in the study, and together they secured funding from the Our Land and Water National Science Challenge Rural Professional Fund. The data collected over time showed that nitrogen losses were driven by rain events originating from urine patches. Good fertiliser management practices were identified as crucial to reducing nitrogen loss.
The project’s community-driven approach demonstrated how water quality monitoring and management programs can improve the reach of monitoring programs. Charlotte is currently working on sustaining the sensors to leverage data for future learning. For more detailed information, please read the project report on the Our Land and Water website.
