Solar-powered automated irrigation system using soil moisture sensing: a prototype for sustainable crop water management in Nigeria

Irrigation inefficiencies persist as a critical barrier to agricultural productivity in rural Nigeria, where farmers face limited access to electricity, automation, and technical expertise. Existing smart irrigation systems often rely on microcontrollers and digital platforms, making them cost-prohibitive and unsuitable for low-resource environments. This study presents a solar-powered automated irrigation system that uses soil moisture sensing to regulate water delivery without microcontrollers. The system integrates a resistive sensor, L298N motor driver, DC pump, battery, and photovoltaic module within a closed-loop analog control circuit. Empirical tests demonstrated prompt irrigation response, continuous operation up to 36 hours without sunlight, and substantial water savings through soil-responsive actuation. Quantitative evaluation, within the constraints of the present prototype, focuses on directly observable metrics such as irrigation response time, continuous runtime without sunlight, and a transparent measurement protocol for estimating relative water use. Where laboratory instrumentation is unavailable, we provide conservative engineering estimates and replication procedures. At a total cost of $38.23 (approximately ₦58,800), the system offers a scalable, energy-autonomous solution for underserved farming communities. This microcontroller-free architecture exemplifies frugal innovation in precision agriculture, providing an accessible pathway for sustainable water management in off-grid, smallholder farming contexts.