Auto Irrigation Using Soil Moisture Sensor

Abstract

An automatic irrigation system has been designed to facilitate the automatic supply of adequate of water from a water tank to plants in gardening area. One of the objectives of this work is to see how human control could be removed from irrigation and also to optimize the use of water in the process. The method employed is to continuously monitor the soil moisture level to decide whether irrigation is needed, and how much water is needed in the soil using Arduino Uno. A pumping mechanism is used to deliver the needed amount of water to the soil. The work can be grouped into five subsystems namely; power supply, sensing unit, control unit, pumping system and display system which make up the automatic irrigation system. A soil moisture sensor was used to detect the moisture of the soil and an ultrasonic sensor was used to determine the level of water in tank; a 9V DC power supply was used to power the Arduino Uno and an AC power supply was used to power the water pump; the control circuit was implemented using relay; the pumping system consisting of a submersible AC water pump was used to pump the water to the plants; and the display system consisting of LCD was used to display the AC water pump state of condition and the water level in tank. System response tests were carried out to determine the range and time taken for the system to irrigate the soil. It is seen that the irrigation in Loamy soil generally took longer duration than the irrigation than in Sandy soil. The system helps to eliminate the stress of manual irrigation and irrigation control while at the same time conserving the available water supply.