Development and Testing of a Low‐Cost Soil Moisture Sensor for Real‐Time Irrigation Scheduling

Effective irrigation scheduling is essential for improved water management in irrigated areas, with soil moisture monitoring recognized as one of the most effective methods. However, challenges such as the high cost of sensors and the difficulties in monitoring large areas hinder their practical application, particularly for smallholder farmers. This study aimed to design and test a locally made low‐cost Arduino‐based soil moisture (ASM) sensor for real‐time irrigation scheduling. The ASM sensor was first tested in the laboratory and then deployed in a wheat field in comparison with a Pycom soil moisture (PSM) sensor and a conventional soil moisture (CSM) method. Initial results indicated that ASM readings were about 13% lower than CSM values, with a linear regression slope of 0.87. After calibration, the slope improved to 1.0, correcting the underestimate. Based on performance metrics including RMSE, relative error, confidence index and index of agreement, the sensor showed a strong linear correlation ( R 2 = 0.97) with CSM both before and after calibration, which was rated as ‘excellent’. The PSM sensor achieved near‐perfect agreement with CSM results, showing the reliability of low‐cost sensor alternatives. Overall, the ASM sensor demonstrated accuracy, cost‐effectiveness and practical suitability, offering a valuable solution for enhancing irrigation scheduling in resource‐limited settings.