Development of a Smart Irrigation Controller Using Soil Moisture Sensors for Crop Farming in Kebbi State

This project develops a smart irrigation controller that uses soil moisture sensors to automate irrigation scheduling for smallholder crop farms in Kebbi State, North West Nigeria. Irrigated agriculture is the backbone of food production in the Kebbi River Basin, yet conventional manual irrigation practices lead to over-watering, water wastage, and energy inefficiency in pumping operations. The designed controller integrates capacitive soil moisture sensors placed at root zone depth in each irrigated field section with an ESP32 microcontroller that reads the soil moisture data and controls motorised solenoid valves for each irrigation zone. When measured soil moisture falls below a crop-specific lower threshold, the valve opens to deliver irrigation water until the upper threshold is reached, at which point the valve closes automatically. A real-time clock module schedules irrigation windows to align with periods of low evaporation demand, typically early morning. Sensor data and valve states are logged to an SD card and transmitted via Wi-Fi to a Blynk mobile application dashboard for remote monitoring and manual override capability. The system was field-validated over a six-week irrigation season on a 0.5-hectare tomato plot in Argungu Local Government Area. Water consumption was 28 percent lower compared to the farmer's previous timer-based irrigation approach, while crop yield and plant health were maintained. System power consumption is supplied by a small solar panel and battery, enabling operation independent of grid supply. Keywords: smart irrigation, soil moisture sensor, water conservation, smallholder farming, Kebbi State.