Development of a Solar-Powered Integrated Wireless Soil Moisture Meter

In this study, we developed a solar-powered integrated wireless soil moisture meter that can easily measure in situ soil moisture, soil temperature, and hydrogen potential (pH) using nature's solar energy. Knowledge of soil moisture content and other relevant soil-specific parameters is essential for irrigation scheduling, fertilizer selection, and fertigation. Also, considering that the electricity supply in some developing countries is either erratic or unavailable, this research aims to bridge the gap in electricity availability and ease of measurement and integrate more soil-specific parameters. The sensor system was developed using the frequency domain (FD) technique for fast response. These parameters were measured sequentially at an interval of about 5 seconds, with the readings displayed simultaneously on a Bluetooth-connected device (e.g., an Android phone) located about 50 meters away from the developed system. The different sensors are classified and adequately labeled to identify the parameter to be measured. The performance evaluation carried out indicated a reasonably functioning device that is cost-effective. The results obtained showed that the system was resourceful as it not only measured the parameters of interest (soil moisture, temperature, and pH) but also gave a prompt response in measurement and transmission. Overall, the developed wireless soil moisture meter provides instantaneous data on pH, moisture, and temperature circulation across soil layers. The system is promising as it can be integrated into large-scale automated irrigation systems for agricultural lands.