13-Development of an auto-irrigation system

Abstract

Water is an essential input for agriculture. With the increasing demand of this resource it has become essential to economize on water, particularly in activities related to agriculture. Scientific irrigation scheduling with automatic control of water application at pre-decided soil water tension is one way to effectively economise the use of water for irrigation. To achieve this an auto-irrigation system has been developed. In this system soil water tension is sensed with a modified manometer type tensiometer. At the pre-decided soil water tension an electrical signal is generated which operates a valve (in case a tank is provided) or motor. A circuit has been designed and fabricated to control the operation of the valves or the motors with respect to these electrical signals. Alternately the design provides for control of irrigation with a pre-programmed timer. The developed circuitry has very low power requirements and can be operated with a 12 volt DC storage battery for a long period of time thus avoiding frequent recharging.