Reducing fouling and emitter clogging in saline water drip irrigation systems by choosing suitable nitrogen fertilizer

The reuse of saline water through drip irrigation presents a sustainable solution to water scarcity, but fouling and emitter clogging are significant obstacles to broader adoption. While fertilization is known to play a key role in fouling, the combined effects of saline water and fertilizer on fouling and clogging remain poorly understood. This study evaluates the impact of five nitrogen fertilizers—urea phosphate, ammonium sulfate, ammonium chloride, calcium nitrate, and ammonium bicarbonate—on emitter performance and fouling in saline water drip irrigation systems. The results show that urea phosphate, ammonium sulfate, and ammonium chloride reduce fouling by 78%, 54%, and 34%, respectively, compared to the control with no fertilization. These fertilizers mitigate fouling by suppressing the formation of calcite, aragonite, and dolomite precipitates, while also preventing particle flocculation, such as quartz and feldspar. In contrast, calcium nitrate and ammonium bicarbonate exacerbate fouling, increasing it by 46% and 96%, respectively, due to their promotion of both crystalline and particulate fouling substances. This study highlights the effectiveness of urea phosphate, ammonium sulfate, and ammonium chloride in minimizing fouling and emitter clogging, offering key insights for advancing fertigation technologies in saline environments.