Performance Evaluation of the Water Advisory for Irrigation Scheduling System (WAISS) Capacitance Soil Moisture Sensor

The agriculture sector accounts for 80% of the total freshwater resource use in the Philippines. With increasing competition for the scarce water supply, it is necessary to utilize water resources efficiently. The application of smart irrigation technology can help achieve higher water use efficiency, increase farm water productivity, and maximize crop yield. To minimize excess or insufficient irrigation water application to crops, and provide more effective and efficient water management, an integrated water monitoring system called Water Advisory for Irrigation Scheduling System (WAISS) was developed. The performance of WAISS was initially evaluated by comparing the soil moisture measurements of its capacitance soil moisture sensor with a commercially developed sensor and the standard gravimetric method. Statistical analysis shows that the low-cost WAISS soil moisture sensors are comparable with the commercially developed sensors with a Percent Error of 5.5% compared to METER ECH2O EC-5's 16.1%. This highlights WAISS' potential as a cost-effective yet reliable alternative for soil moisture monitoring.