A Sensor and Actuator System for Evapotranspiration Based Irrigation Scheduling System

Overwatering and underwatering are problems in maintaining healthy plant growth in farming. To solve such problem, a sensor and actuator system for optimal irrigation schedule needs to be implemented with regards to cultivation environmental parameters. In this research, an evapotranspiration-based irrigation scheduling system for a screen house has been designed and implemented. The system consists of sensor node that measure the weather condition such as air temperature and humidity, solar radiation, and wind speed to estimate the reference evapotranspiration rate (ETo) in the screen house. This ETo value is used to calculate the amount of water loss in the last irrigation session. In the next irrigation session, actuator node will run the irrigation system according to the calculated water amount from the system. The weather and irrigation condition data are monitored by user through mobile app that supported by cloud server and gateway to link the user with sensor and actuator nodes in the screen house. Based on this research, the system designed and implemented already able to carry out its functionality in doing ETo calculation and perform irrigation according to calculated water amount. The accuracy of air humidity measurement (±4.00
^%
RH), sunlight intensity measurement (±4.07
^%
), and water application measurement (±1.53%) has met the specification. Meanwhile the accuracy of air temperature measurement (±0.65°C) and wind speed measurement (±0.54ms
^-1
) have not met the specification, yet, and need further testing.