AUTOMATIC IRRIGATION SCHEDULING BY REMOTECONTROLLED TENSIOMETERS UNDER ARID CLIMATICCONDITIONS

Abstract

A closed loop, remote sensing and control system for automatic irrigation scheduling was developed and implemented to demonstrate the effect of automatic scheduling on water conservation. The system was based on continuous sensing of the soil water potential, using transducer-tensiometers located at various locations and depths throughout the field area. The collected data were continuously analyzed for specified threshold level of soil matric potential to decide when to start and stop a center pivot irrigation system on wheat. When the condition for start or stop irrigation was met, the computer automatically sent commands to start (or stop) the irrigation cycle. The system worked satisfactorily under arid conditions.The results of the automatic scheduling technique demonstrated that the average yield for three seasons increased by 8% and the average water saving was 24% as compared with that obtained by common scheduling practice. The average reduction in machinery and equipment working hours was 26.8 %.