Water scarcity and deficiency of trace elements (e.g., Cu and Mn) in soils of arid and semi-arid areas are major constrains to crop growth and development. The application of brackish water drip irrigation system (BWDIs), coupled with trace elements, is probably an effective way to solve this problem. However, fouling problems caused by trace elements in BWDIs were inevitable. Therefore, this paper evaluates the mechanism of different types of trace element chelated fertilizers on the fouling of emitters in BWDIs by using long-period, high-frequency periodic flow monitoring and mineral fraction analysis. The influence of chelated fertilizers such as copper (EDTA-Cu) and manganese (EDTA-Mn), and traditional micro-fertilizers copper sulfate (CuSO₄) and manganese sulfate (MnSO₄) on emitter fouling in BWDIs were investigated. Results suggested, compared with CK, the EDTA-Cu effectively alleviated the emitter fouling, increasing the average discharge ratio (Dra) and Christiansen coefficient of uniformity (CU) by 21.0%− 28.9% and 36.7%− 67.6%, respectively. Due to the strong adsorption ability, EDTA-Cu adsorb the Ca²⁺ and Mg²⁺ in BWDIs, which enhanced the structural stability, reduced the flocculation and deposition ability in the fouling, and indirectly reduced the content of calcium and silica fouling. In addition, compared with CK, the EDTA-Mn significantly aggravated the emitter fouling in BWDIs, decreasing the Dra and CU by 18.2%− 22.5% and 24.5%− 43.1% respectively. EDTA-Mn directly increased the content of Ca²⁺ and Mg²⁺ in BWDIs due to strong flocculation, which destroyed the morphology of EDTA-Mn chelates and indirectly increased the content of calcium silica fouling (calcite, muscovite, k-feldspar, dolomite and chlorite), thus reduced the anti-clogging ability of BWDIs. Considering these results, this study does not recommend the application of EDTA-Mn for manganese fertilizer in BWDIs. This study provides a new perspective on the rapid application of micronutrient fertilization in BWDIs, with potential implications for sustainable development in arid and semi-arid areas.

干旱和半干旱地区土壤缺水和微量元素（如铜、锰）缺乏是制约作物生长发育的主要因素。微咸水滴灌系统（BWDIs）的应用，加上微量元素，可能是解决这一问题的有效途径。然而，BWDIs 中微量元素造成的污染问题是不可避免的。因此，本文通过长周期、高频周期性流量监测和矿物分数分析，评估不同类型微量元素螯合肥料对 BWDI 排放源结垢的机理。螯合肥料如铜 (EDTA-Cu) 和锰 (EDTA-Mn) 以及传统微肥硫酸铜 (CuSO₄) 和硫酸锰 (MnSO ₄ ) 对 BWDI 发射器结垢的影响进行了研究。结果表明，与 CK 相比，EDTA-Cu 有效缓解了发射器结垢，平均排放比 (Dra) 和 Christiansen 均匀系数 (CU) 分别提高了 21.0%- 28.9% 和 36.7%- 67.6%。由于吸附能力强，EDTA-Cu吸附Ca ²⁺和Mg ²⁺在BWDIs中，提高了结构稳定性，降低了污垢中的絮凝和沉积能力，间接降低了钙和二氧化硅污垢的含量。此外，与 CK 相比，EDTA-Mn 显着加重了 BWDI 中的发射器污染，使 Dra 和 CU 分别降低了 18.2%- 22.5% 和 24.5%- 43.1%。EDTA-Mn由于强烈的絮凝作用直接增加了BWDIs中Ca ²⁺和Mg ^{2+的含量，破坏了EDTA-Mn螯合物的形态，间接增加了二氧化硅污垢（方解石、白云母）的含量。}、钾长石、白云石和绿泥石），从而降低了 BWDI 的抗堵塞能力。考虑到这些结果，本研究不建议将 EDTA-Mn 用于 BWDI 中的锰肥。本研究为在 BWDI 中快速应用微量营养素施肥提供了新视角，对干旱和半干旱地区的可持续发展具有潜在意义。