An IoT Based, Low-Cost, Trunk Frequency Measurement System for Plant Health Monitoring

The continuous increase in human population is leading the world towards the eventually increasing demand for food production. Therefore, developing advanced Smart Agriculture technologies to boost crop yields has become crucial. In this work, a low-cost system for plant health monitoring based on measurements of stem frequency, soil-moisture level and other environmental parameters is proposed. A signal is generated and propagated through a plant and the corresponding data at transmitter Microcontroller Unit (MCU) is collected through Internet of Things (IoT) network. Using the collected data, the stem frequency is computed by Fast Fourier Transform (FFT). The plant was placed in a closed environment with nearly constant temperature and humidity levels throughout the experiment. A strong correlation is found between soil-moisture level and stem frequency thus indicating the later as a key representation of water-stress levels. This also demonstrates that calculating the stem frequency through FFT and water stress level through soil-moisture sensor is a low-cost and a simple solution for plant health monitoring.