Effect of fertilization on emitter clogging in drip irrigation using high sediment water: Perspective of sediment discharge capacity

Emitter clogging is a major issue that restricts drip irrigation technology with high-sediment loaded water. Traditional anti-clogging method using water filtration is not only costly but also consumes an excessive amount of energy. This study provided a new anti-clogging method for drip irrigation systems by directly desilting sediment from the emitter flow channel. The emitter SDC was assessed using three types of fertilizers [Urea (UN), ammonium poly-phosphate (APP), and mono-ammonium phosphate (MAP)] and a control group (CK, no fertilizer). The results showed that most sediment can be discharged through the emitter flow channel. Nitrogen fertilizer applications significantly affected (P<0.05) the emitter SDC. Both APP and MAP significantly reduced the emitter SDC, causing an average decrease of 0.61μm-1.21μm in the control threshold for particle size μ0 and 0.55%−1.67% in the sediment discharge rate (φe), while the sediment deposition and discharge ratio (φ) increased by 0.004%−0.040% on average. However, UN application effectively increased the emitter SDC, with an increase of 0.45μm-0.53μm in the control threshold for particle size μ0, 0.70%−5.99% in φe, while the sediment deposition and discharge ratio (φ) decreased by 0.002%−0.003%. The relative average flow rate (Dra) among different fertilizer treatments demonstrated DraUN＞DraCK＞DraMAP＞DraAPP. The findings suggested that the emitter SDC can be improved by using suitable fertilizer type. This study clarified the effect of fertilizer on the sediment discharge capacity of emitter, with implications for the management of high-sediment loaded water in irrigation.