The beneficial effect of fertigation with acidic fertilizers to protect emitters from chemical and biological clogging might be inhibited by improper fertigation modes. An on-site drip irrigation experiment was conducted to investigate the injection strategies of phosphorus (P)-coupled nitrogen (N) fertigation and water salinity on clogging of emitters with plain channel and labyrinth structures. The results demonstrated that the H⁺ in acidic P fertilizer solutions inhibited the precipitation of carbonate and phosphate simultaneously. However, a weak acidic P fertilizer could no longer protect the emitters from clogging effectively under saline water with an electrical conductivity (EC) exceeding 2 dS m⁻¹ because the phosphate sediments accounted for more than 80% of the total clogging substances. A strategy of applying a weak acidic phosphate fertilizer following N fertigation performs better in reducing emitter clogging than fertigation using N and phosphate fertilizers together. The target pH values were obtained as 6.0, 4.0, and 3.0 for protecting emitters from clogging for drip irrigation systems applying irrigation water with an EC of 0.5, 2.0, and 4.0 dS m⁻¹, respectively. An optimal fertigation mode for emitter clogging control should consider water quality, type and pH value of fertilizer, and emitter type comprehensively.

中文翻译：

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基于盐水应用的滴灌管堵塞控制确定磷耦合氮肥灌溉的注入策略*

不恰当的施肥模式可能会抑制酸性肥料施肥保护排放器免受化学和生物堵塞的有益效果。进行了现场滴灌试验，研究了磷（P）耦合氮（N）施肥和水盐度对平原通道和迷宫结构的发射器堵塞的影响。结果表明，酸性磷肥溶液中的H ^{+同时抑制了碳酸盐和磷酸盐的沉淀。}然而，弱酸性磷肥不能再有效地保护发射器在电导率（EC）超过 2 dS m ^{-1的盐水下不被堵塞。}因为磷酸盐沉积物占堵塞物总量的80%以上。在施氮肥后施用弱酸性磷肥的策略在减少灌水器堵塞方面比同时施氮肥和磷肥施肥效果更好。目标 pH 值分别为 6.0、4.0 和 3.0，以保护滴灌系统使用 EC 分别为 0.5、2.0 和 4.0 dS m ^-1的灌溉水的滴灌系统免受堵塞。控制灌水器堵塞的最佳施肥方式应综合考虑水质、肥料种类和pH值以及灌水器类型。