EFFECT OF IRRIGATION WATER QUALITY ON EMITTER'S CLOGGING PERCENT

Drip irrigation systems have reached to a high level of technology, but still faced a remarkable operational problem named emitter clogging. Emitter clogging can affected distribution uniformity and the system performance, which has direct relationship with water quality. Three types of emitters (pressure compensating, long path and turbo-key) with nominal discharges 4, 6 and 8 L/h, respectively were tested under three types of irrigation water (Nile, Drainage and Fertilized water). Each test was carried out under four levels of operating pressure (75, 100, 125, 150 kPa). Emitter spacing was 50cm and six laterals of 16mm diameter and lateral spacing of 75 cm and 10m long was used for each treatment. Drip irrigation system was constructed in Agricultural Engineering Department; faculty of agriculture; Menoufia University during 2015. The main objective was to evaluate emitter clogging percent and it's changing with operating periods for each treatment. The results showed that turbo key emitter achieved the lowest percent of clogging with Nile water (8.12%) after 181 hours of operating period; at 100 kPa of operating pressure. In case of Drainage water at 100 kPa, the emitter clogging percent was (12.24, 21.33 and 70.75%) for turbo key, long path and pressure compensating, respectively after 181 hours of operating period. With Fertilized water at 100 kPa, the clogging percent was (11.38, 19.12 and 34.50%) for turbo key, long path and pressure compensating, respectively. Increasing the operating pressure led to remove deposits outside the emitter and the clogging percent decreased, as occurred with turbo key emitter. Both of water quality and emitter type play an effective role in maintaining drip irrigation system efficiency for a long time.