Design and implementation of a solar-powered automatic agriculture meter for coffee nursery bed management in Uganda

Small-scale coffee nursery beds in Uganda are still managed largely by hand, and the resulting inconsistency in watering and monitoring contributes to low germination and weak seedlings. This project addresses that gap by designing and implementing a solar-powered automatic agriculture meter that monitors and controls the environmental conditions most critical to seedling survival: soil moisture, soil pH, ambient humidity, and temperature. The system is built around an Arduino Mega 2560 microcontroller that integrates low-cost sensors, an I2C-interfaced 16x2 LCD, and a relay-driven water pump, all powered by a solar panel, rechargeable battery, 7805 voltage regulator, and XL6009 buckboost converter. Unlike prior low-cost irrigation prototypes that address moisture control in isolation, this system combines real-time multi-parameter monitoring with automated irrigation in a single off-grid unit tailored to the coffee nursery context, extending existing solar-irrigation research into a domainspecific tool for rural Uganda. Testing over a 12-hour period showed the pump activating reliably below a 40% moisture threshold, stable LCD reporting, and consistent solar-battery performance. The prototype demonstrates that dependable, low-maintenance automation is achievable at low cost, offering smallholder coffee farmers a practical route to healthier seedlings, reduced labour, and more sustainable nursery bed management