- There are many possible benefits that can arise from the ability to take real-time measurements of soil water nitrate concentrations in a field, from ecological to agricultural to industrial reasons. In order to achieve this, we adapted a NitraLED sensor with a ceramic porous cup in order to allow diffusion to occur between the soil water and the water inside the porous cup. The adapted sensor measured known concentrations of nitrate solution, saturated sand, and unsaturated sand. Expected equilibration curves, equilibration time, and final expected concentrations were observed consistently in solution and saturated conditions, but not in the unsaturated condition. Unsaturated conditions readings only read about 60% of the concentration that it should have and took around 3.5x as long to reach equilibrium. This shows that there is potential for adapted water nitrate sensors to be used to take real-time measurements of soil water nitrate, but there may be limitations in their effectiveness depending on the water content of the soil.
- Keywords: porosity, diffusion, saturation, nitrate, UV-LED