Abstract: The variable‑rate pesticide application system has several advantages of enhancing  pesticide utilization rate, reducing pesticide residue levels, and reducing environmental pollution. Depending on the control mechanism employed, it can be categorized into three main typessuch as liquid concentration adjustment, pressure adjustment and flow adjustment. Particularly, the variable flow spraying system, leveraging pulse width modulation (PWM) technology, has garnered significant attention domestically and internationally in recent years owing to its broad flow adjustment range and consistent droplet characteristics. Nevertheless, during variable spraying operations, challenges such as nozzle opening and closing, pump pulsations, and valve switching actions can induce fluctuations in pipeline pressure, leading to compromised atomization quality and inaccurate dosing. This paper reviews the current research landscape, focusing on three key aspects suchas the types of variable pesticide application systems, investigations into system pressure fluctuation characteristics and approaches and equipment for mitigating pressure fluctuations. Furthermore, it delves into the composition, advantages, and limitations of variable pesticide application systems employing liquid concentration regulation, pressure regulation and flow regulation. Emphasis is placed on elucidating the pressure fluctuation characteristics observed near pipelines and nozzles in both domestic and international pesticide application systems. Various methods and equipment for suppressing pressure shocks, such as reflux pressure stabilization, air valves, and pressure‑stabilizing nozzles, are extensively discussed. The study also highlights the challenges associated with the accuracy of variable pesticide application systems and the ongoing development of pressure‑stabilizing products in China. Finally, it outlines future prospects, offering insights for enhancing the precision and intelligence of variable spraying systems.

Key words: variable spraying, liquid concentration regulation, pulse?width modulation, pressure fluctuation characteristics, pressure fluctuation elimination

摘要： 变量施药系统具有提高农药利用率、降低农药残留、减轻环境污染等优点，根据控制方式可分为药液浓度调节式、压力调节式和流量调节式。基于脉宽调制技术的变流量式施药系统因流量调节范围广、雾滴特性稳定等优点成为国内外研究热点，但在变量施药过程中因部分喷头启闭、泵源脉动、阀体开关动作等会造成管路压力波动，导致雾化质量差，药量不精准等亟待解决的问题。从变量施药系统类型、系统压力波动特性研究、系统压力波动抑制方法与装备方面综述国内外研究现状，分析总结药液浓度调节式、压力调节式、流量调节式变量施药系统的构成、优势和缺陷，重点阐述和归纳国内外施药系统中管路和喷头附近压力波动特性，主要介绍回流稳压、空气阀、稳压喷嘴等压力冲击抑制方法和装备，指出我国在变量施药系统精确性、变量施药系统压力稳定产品开发等方面的不足并提出展望，为实现变量施药系统的进一步精准化、智能化提供思路。

关键词: 变量施药, 药液浓度调节, 脉宽调制, 压力波动特性, 压力波动消除