田间农药雾滴精准采样技术与发展趋势

采用植保机械喷施化学农药仍是病虫害防治最为有效的手段。喷施过程中,农药雾滴精准的采集并测定沉积、流失飘移量,对于优化植保机械的作业参数、提高农药利用率具有重要意义。该研究综述分析了室内与田间采样过程中不同类型采样器的优缺点,并分析采样效率、采样器的布置及采样条件等因素对雾滴沉积、流失飘移采样结果的影响。针对当前的采样方法,该研究提出了未来在农药雾滴采样方面的5点要求与展望,包括提高采样的准确性、提高采样方法和采样设备的标准化、增加对农药有效成分雾滴运动规律的研究、研发新型的采样传感器以提高采样效率、建立植保无人飞机喷施雾滴沉积、飘移模型。综上,通过更为标准化和精准的采样,获取可比较、准确度高的农药雾滴沉积与流失飘移数据,可为中国农药使用量"零增长"提供科学技术指导。

Current status and prospects of precise sampling of pesticide droplets

Plant protection machinery to spray pesticides is one of the most effective pest control methods in agriculture. It is necessary to accurately collect and measure the amount of droplets deposition, loss, and drift in the spraying process of pesticides, thereby optimizing the operating parameters of plant protection equipment, while improving the utilization rate of pesticides. Various samplers are available at present for sampling spray deposition, loss, and drift droplets. The selection of the samplers should meet the following requirements. Firstly, high collection efficiencies of samplers were required for the droplets of different sizes in relatively low wind speeds; Secondly, the samplers were not easy to saturate, with a certain sampling volume or area to sample sufficient droplets. A certain sampling volume or area can be used to calculate the deposition per unit area; Thirdly, the samplers should not react with active ingredients or tracers, particularly with high sampling efficiency, and stable recovery rate, where the resulting data can be quantitatively analyzed; Fourthly, the cheap samplers are easy to handle under field conditions. In this study, four types of samplers classified by the analytical approaches were introduced, including the type of image processing, chemical analysis, sensors, and rest. There were special precautions for each sampler. The selection of image processing software, correction of scanned data, and the limitations should be noticed in the type of image processing samplers. Much attention should be paid to the selection of samplers, dye or fluorescent tracer, and the volatility of pesticide active ingredients in the type of chemical analysis samplers; The type and applied scenarios were critical for each sensor and accuracy of sensors in the type of sensor samplers. In addition, there was some adhesion, rebound, or breakage failure, further detrimental to the sampling efficiency, when the droplets came into contact with the sampler. Especially for the type of chemical analysis samplers, special attention should be paid to sampling efficiency and recovery. Except for the selection of samplers, there was a significant effect on the placement position, transportation, and preservation of samplers, meteorological requirements, and sampling test sites. Five requirements or prospects were proposed for the current sampling in the future, including (a) to inspect plant protection machinery before the test, and determine the sampling efficiency and recovery rate of selected samplersfor a high accuracy of sampling, (b) to standardize the sampling or samplers in the development of fast suitable for field sampling; (c) further studies focused on the deposition of droplets containing pesticide active ingredients, (d) to develop new sampling sensors for high sampling efficiency, and (e) to establish a deposition and drift model of plant protection drones. In any way, the standardized and accurate sampling is needed to obtain comparable and highly precise data of pesticide deposition. The finding can make a great contribution to improving the current utilization rate of pesticides, particularly providing potential scientific and technical guidance for the "zero growth" of pesticide usage.