Remote Soil Moisture Sensing Using Radio-frequencies

The Challenge

Sensing soil moisture is a critical measurement in precision agriculture. Many of the existing sensing devices on the market (capacitance probes) require digging into the soil for a point measurement. This installation process and the permanent positioning of the sensors create a challenge in the real world of agriculture. Also, rather than a point measurement, a distributed measurement of soil moisture across a field is needed.

The Solution

Radio frequency waves are known to interact with specific materials as it propogates. In the context of soil moisture, when radio waves travel as surface waves on the ground/air interface, a positive correlation has been previously detected with RF signal strengths. These early demonstrations were done many years ago, and since then low-frequency RF communication devices such as LoRa have emerged and may offer some interesting solutions. As such this project looks to measure soil moisture content across a field using RF transmitters and receivers. If successful, it will provide insights into non-contact distributed soil sensing technologies.

University Partners