Abstract Phosphorus (P) is an essential element for crop production. Drip irrigation (DI) system, mainly because of its high precision, allows effective application of water-soluble P-fertilizers. However, consecutive input of P-fertilizer would react with ions in the water source, especially when using the saline water containing high concentration of ions. Consequently, the integration of P fertilizer and saline water results in more complicated and serious DI emitter clogging, which may damage the whole irrigation system. Therefore, an in-situ field study was conducted to study the impacts of saline water concentrations (2 g L−1 and 4 g L-1) and water-soluble P-fertilizer types (urea phosphate, UP; and mono-potassium phosphate, MKP) on DI system performance. The results indicated that both UP and MKP application aggravated the emitter clogging process, and decreased the system discharge variation ratio (Dra) and Christiansen coefficient of uniformity (CU) by 2.62 %–11.7 % and 1.89 %–7.94 %, respectively. UP treatments performed better than MKP treatments in anti-clogging abilities, as it increased the DI system Dra (4.81 %–5.78 %) and CU (2.98 %–3.59 %). Besides, the impacts were significantly enhanced by higher water salinity. The system performance indicators were closely related to the chemical precipitations inside emitters, especially the relative contents and variations of the primary components (carbonates, quartz and silicates). UP performed better than MKP mainly because it lowered water pH and thus significantly reduced precipitation. Overall, clogging parameters (Dra and CU), clogging substances and the components of fertigation treatments all showed positive linear correlations with controlled treatments that without fertilizer applied (CK_2 and CK_4). The slopes of the fitting curves and significance analysis results combined demonstrated that, the water salinity had larger impact on emitter clogging process than fertilizer types. Present study offered references to fertilizer application using saline water to maintain drip irrigation system’s benefits.

中文翻译：

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磷肥对咸水滴灌系统滴头堵塞的影响

摘要 磷（P）是作物生产的必需元素。滴灌（DI）系统，主要是因为其精度高，可以有效地施用水溶性磷肥。然而，连续投入的磷肥会与水源中的离子发生反应，尤其是在使用含有高浓度离子的盐水时。因此，磷肥和盐水的结合导致更复杂和严重的DI发射器堵塞，这可能会损坏整个灌溉系统。因此，进行了现场实地研究，以研究盐水浓度（2 g L-1 和 4 g L-1）和水溶性磷肥类型（磷酸尿素，UP；和磷酸二氢钾）的影响。 , MKP) 对 DI 系统性能的影响。结果表明，UP 和 MKP 的应用都加剧了发射器堵塞过程，并使系统流量变化率（Dra）和克里斯蒂安森均匀系数（CU）分别降低了 2.62%–11.7% 和 1.89%–7.94%。UP 处理在抗堵塞能力方面的表现优于 MKP 处理，因为它增加了 DI 系统 Dra (4.81 %–5.78 %) 和 CU (2.98 %–3.59 %)。此外，较高的水盐度显着增强了影响。系统性能指标与发射体内部的化学沉淀密切相关，尤其是主要成分（碳酸盐、石英和硅酸盐）的相对含量和变化。UP 比 MKP 表现更好，主要是因为它降低了水的 pH 值，从而显着减少了沉淀。总体而言，堵塞参数（Dra 和 CU），堵塞物质和施肥处理组分均与不施肥对照处理（CK_2和CK_4）呈正线性相关。拟合曲线的斜率和显着性分析结果表明，水体盐度对灌水器堵塞过程的影响大于施肥类型。本研究为使用盐水施肥以维持滴灌系统的效益提供了参考。