This book will helpful to students of agricultural engineering who are working and researching the area of automatic irrigation. A soil moisture sensor has been developed for measurement of soil moisture and management of irrigation. This book contains three major parts. (1) design of soil moisture sensor (2) determine the suitable level sensor to sensing the height of water level depletion with respect to soil moisture content and interface with controller and to control water application. (3) development of user friendly device and interface that allows easy control of the system.