Nitrate discharge measurements

Nitrate discharge measurements

Getting insight into water and nutrient flows in the unsaturated soil can be crucial understanding biological processes and interactions related to carbon and nitrogen cycles, and ultimately the balance and long-term survival of ecosystems.

Although multiple sensors and analysis tools have been made in the fields of hydrology, soil science and ecology; an integrated sampling and sensing system which encompasses these various domains has yet to be developed. DMR is part of the Horizon2020 project FutureArctic, and our part of the project is the development of a hardware/software package that focused on the development of an automated soil sampler for measuring sub-soil nutrient flows.

The system at hand manages to autonomically sample soil water from the unsaturated zone and perform the following measurements in real time:

  • Nitrate concentration (down to 0.1ppm NO3-N)
  • Soil potential
  • Soil moisture
  • Soil temperature
  • CO2 concentration
  • Rain fall
  • Atmospheric pressure
  • Vacuum pressure
  • Sampling flow rate

For the actual sampling process, a porous steel lysimeter is used to which a certain vacuum is applied to suck out the soil water. Depending on the use case, the system can be set to operate at a desired flow rate or a at desired vacuum pressure.

Since this project has an Arduino MKR NB 1500 at its core, it is very flexible and equipped with a narrowband modem, which allows it to wirelessly send data to the cloud using very little energy.

This low-power characteristic will also be a significant part of the further development towards the fruition of the PhD project, where a goal will be to maximize the system’s self-sufficiency and smart decision making in terms of energy consumption.

For more information about the project or developed device please contact our experts below. 

Poul Larsen
Department manager
+45 30 22 50 55