WATER CONSERVATION THROUGH IRRIGATION SCHEDULING UNDER ARID CLIMATIC CONDITIONS

A field experiment was carried out on wheat crop at the project sites of Hail Development Company (HADCO), about 500 km north-west of Riyadh , Kingdom of Saudi Arabia. Four centre pivot circles (each 54 ha in ar ea) were used in the study. A model based on the Modified Penman Metho d (FAO version) was developed and used for irrigation scheduling. The required micro-climatic parameters were continuously monitored by an a utomatic weather station installed at the site and transmitted to a co mputer for processing and analyses. The results of the experiment indi cated that an appreciable amount of water (25%) was saved as compared to the irrigation practice adopted by HADCO, and the yield is increase d significantly by using this technique of scheduling. In addition, th e conservation of water results in reducing the working hours of the e quipment and labour.