An in-situ accelerated experimental testing method for drip irrigation emitter clogging with inferior water

Abstract

Emitter clogging has become a bottleneck in the application and promotion of inferior water drip irrigation technology. Understanding the detailed emitter clogging process is the precondition and basis for solving clogging issue. However, the existing indoor simulated experiments have the disadvantages in unnecessary effect on the results, and the in-situ experimentation is difficult due to the long experiment period. Therefore, this paper proposed an in-situ accelerated (ISA) experimental testing method for studying the emitter clogging behaviors in drip irrigation systems with inferior water source. Its feasibility was verified in Dengkou in Inner Mongolia, and a comparative study was performed to examine the differences and correlations between the ISA method and the normal intermittent (NI) method for drip irrigation using Yellow River water (YRW) and brackish water (BRW). The results indicated that the drip irrigation emitter clogging behaviors via the ISA method were relatively conservative. The values of randomness of clogging occurrence (△FQt), emitter clogging degree (EC), emitter discharge variation (qvar), clogging substance on the internal laterals (CSL) and clogging substance inside emitters (CSE) were lower than those of the NI method by 24–57, 64–110, 58–121, 16–38 and 14–32%, respectively. The average discharge variation ratio (Dra), Christiansen coefficient of uniformity (CU) and statistical uniformity coefficient (Us) were 7–13, 15–23 and 17–39% higher than those of the NI, respectively. Besides, the experimental results under the two modes (ISA and NI) had significant linear correlation (0.98 > R2 > 0.75). Thus, the ISA experimental results could be converted into those under NI mode using the linear model, without considering the effects of emitter type nor the water quality. This result indicated that the ISA method could accurately reflect the clogging behaviors of the drip irrigation emitter.