Development of a Low-Cost Solar-Powered Wireless Sensor Network for Real-Time Soil and Water Quality Monitoring in Akwa Ibom State, Nigeria

Abstract

This study presents the design, development, and pilot validation of a low-cost Wireless Sensor Network (WSN) prototype for real-time monitoring of soil and water quality parameters in selected communities of Akwa Ibom State. The system integrates multi-parameter soil and water sensors with an ESP32-based edge processing unit, LoRa long-range communication, and a cloud-based analytics platform for real-time visualization and alert generation. A 30-day pilot deployment was conducted across five communities to evaluate system performance and environmental conditions. Soil analysis revealed slightly acidic conditions (pH 5.1–5.9), moderate nitrogen deficiency, and localized potassium depletion. Water quality results showed spatial variation in turbidity (14-30 NTU), dissolved oxygen (4.3-6.2 mg/L), and conductivity (180-420 µS/cm), indicating potential anthropogenic influence in coastal and industrial zones. Validation against standard laboratory measurements (n = 60 paired samples per parameter) demonstrated strong agreement, with high correlation coefficients (r = 0.88-0.96, p < 0.001), low RMSE values, and acceptable Bland-Altman limits of agreement within defined sensor tolerances. A cost-benefit analysis showed an 83.5% reduction in 5-year lifecycle cost compared to conventional monitoring systems. The findings confirm that the proposed WSN provides a reliable, scalable, and economically sustainable solution for environmental monitoring and precision agriculture applications.