A low-cost modular precision irrigation system for resource-constrained environments

Abstract

Abstract
Precision irrigation technologies have emerged as effective tools for optimizing water use and improving crop productivity. However, many existing systems remain costly and technically complex, limiting their adoption among smallholder farmers in resource-constrained environments. This study presents the design and field evaluation of a low-cost modular precision irrigation system aimed at improving irrigation efficiency while maintaining affordability. The proposed system integrates soil moisture, temperature, and humidity sensors with ESP32-based microcontrollers organized in a master-slave architecture. A custom-designed 5V reduction electric valve, significantly cheaper than conventional solenoid valves, is used to control irrigation water flow. The system further incorporates a soil-crop database and a mobile application (GEPA Mobi) to support remote monitoring and adaptive irrigation scheduling. The system was deployed and tested across five irrigation farms in Northern Uganda for a period of 100 weeks, during which soil moisture, temperature, and humidity data were continuously collected. Results demonstrate that the system reliably monitored environmental conditions and supported automated irrigation decision-making with minimal maintenance requirements. The proposed reduction electric valve reduces irrigation hardware costs from approximately $50 to $25, making the system significantly more affordable for smallholder farmers and scalable for large farms with almost 50% reduction in cost. Overall, the developed system provides a scalable, energy-efficient, and cost-effective precision irrigation platform suitable for resource-constrained agricultural environments. The integration of modular hardware, cloud connectivity, and crop-specific irrigation thresholds enhances its adaptability across different crops, soil types, and farm sizes.