Smart Irrigation System Using Arduino and Soil Moisture Sensor

Efficient water management is essential in modern agriculture because conventional irrigation methods commonly depend on manual operation or fixed schedules. Such approaches may cause overwatering or underwatering, resulting in water wastage, increased labour effort, and reduced crop productivity. This paper presents a Smart Irrigation System using an Arduino UNO, soil moisture sensor, relay module, water pump, and external power supply. The soil moisture sensor continuously monitors the moisture condition of the soil and provides an analog signal to the Arduino. The controller compares the sensed value with a predefined threshold. When the soil condition indicates dryness, the Arduino activates the relay and the water pump supplies water to the plants. When sufficient moisture is reached, the relay is deactivated and the pump is switched OFF automatically. The system therefore provides real-time irrigation control with minimal human intervention. Experimental testing described in the source project showed consistent operation for dry and wet soil conditions, with the pump turning ON for dry soil and OFF after sufficient moisture was reached. The proposed system is simple, low-cost, and suitable for small-scale applications such as gardens, greenhouses, and agricultural fields.