Abstract: A furrow guide on one end of the moving pipe of an irrigation system determines the horizontal distance from the end of the pipe to a furrow. The determination of this horizontal distance is used to control functions of the irrigation system such as to guide the direction of travel of the traveling pipe. Also, the furrow guide is used with an automatic irrigator to guide the valve opener to the valve. The automatic irrigator has all elements operating automatically, including the starting of the engine and the complete movement of the system.