Effect of Irrigation Management, Flow Rate and Operating Pressure on Clogging of Pressure Regulator Emitters

Emitters clogging is one of the most important problems in the operation of drip irrigation systems and also it is one of the main obstacles to the development of this irrigation method. To investigate the effect of discharge, operating pressure and management of irrigation system on clogging, emitters with discharges of 4 and 8 l/h, under three different operating pressures (1.0, 2.0 and 3.0 bar) and under three irrigation management methods (four, two and one times flow cutoff in every four hours operation) were tested for 132 hours. Accordingly the research included 18 treatments with four replicates which lasted for four months from July to October. In order to monitor the clogging in a limited time, 0.5 g/l of chalk was added to the water reservoir of the system. After 12, 36, 84 and 132 hours of the system operation, the clogging percentage of 4 l/h-emitter was 1.49, 1.12, 1.14, and 1.07 times more than the clogging percentage of 8 l/h-emitter. Discharge reduction in emitters under higher operating pressure was less than that in emitters under lower operating pressures. After 132 hours of system operation, the clogging percentages in emitters under operating pressures of 1.0, 2.0 and 3.0 bar were 91, 86 and 17, respectively. The effect of irrigation management method in treatments under operation pressure of 1.0 and 2.0 bar did not show a clear trend. Although, there was no meaningful difference between experimental treatments in emitters under 3.0 bar operating pressure, but in those with less flow interruption per the same operating time, less clogging was observed.