Effect of flushing frequency on emitter clogging in microirrigation with effluents

Abstract

Flushing is an important maintenance task that removes accumulated particles in microirrigation
laterals that can help to reduce clogging problems. The effect of three dripline flushing frequency
treatments (no flushing, one flushing at the end of each irrigation period, and a monthly flushing during
the irrigation period) was studied in surface and subsurface drip irrigation systems that operated using a
wastewater treatment plant effluent for three irrigation periods of 540 h each. The irrigation systems had
two different emitters, one pressure compensating and the other not, both molded and welded onto the
interior dripline wall, placed in laterals 87 m long. Dripline flow of the pressure compensating emitter
increased 8% over time, while in the nonpressure compensating emitter, dripline flow increased 25% in
the surface driplines and decreased 3% in the subsurface driplines by the emitter clogging. Emitter
clogging was affected primarily by the interactions between emitter location, emitter type, and flushing
frequency treatment. The number of completely clogged emitters was affected by the interaction
between irrigation system and emitter type. There was an average of 3.7% less totally clogged emitters in
flushed surface driplines with the pressure compensating emitter as compared to flushed subsurface
laterals with the nonpressure compensating emitter