This study focuses on the implementation of an IoT-based sensor system for precision irrigation management in agricultural fields. The authors developed a low-cost sensor monitoring system (LOCOMOS) that measures soil moisture at multiple depths and provides real-time irrigation recommendations through a user-friendly website and smartphone app. The system was calibrated using laboratory experiments to ensure accurate measurements in different soil types, including sand and loamy sand. Field demonstrations were conducted in corn, blueberry, and tomato fields in Michigan, USA. The results showed that LOCOMOS effectively evaluated existing irrigation practices and provided recommendations to optimize water use. In corn and blueberry fields, the system helped reduce overirrigation and improve yields and quality. In the tomato field, the automated irrigation system applied 30% less water while maintaining the same yields and quality, demonstrating the potential for significant water savings. The study highlights the importance of IoT technology in improving irrigation efficiency and sustainability in agriculture.This study focuses on the implementation of an IoT-based sensor system for precision irrigation management in agricultural fields. The authors developed a low-cost sensor monitoring system (LOCOMOS) that measures soil moisture at multiple depths and provides real-time irrigation recommendations through a user-friendly website and smartphone app. The system was calibrated using laboratory experiments to ensure accurate measurements in different soil types, including sand and loamy sand. Field demonstrations were conducted in corn, blueberry, and tomato fields in Michigan, USA. The results showed that LOCOMOS effectively evaluated existing irrigation practices and provided recommendations to optimize water use. In corn and blueberry fields, the system helped reduce overirrigation and improve yields and quality. In the tomato field, the automated irrigation system applied 30% less water while maintaining the same yields and quality, demonstrating the potential for significant water savings. The study highlights the importance of IoT technology in improving irrigation efficiency and sustainability in agriculture.