Field trials were performed to evaluate various techniques for measuring spray deposition and aerial drift during spray application to paddy field.The application of a spraying agent containing the fluorescent dye Rho...Field trials were performed to evaluate various techniques for measuring spray deposition and aerial drift during spray application to paddy field.The application of a spraying agent containing the fluorescent dye Rhodamine-B was applied by an unmanned aerial vehicle(UAV)which flew at a height of 5 m,a speed of 3 m/s,and the wind speed of 3 m/s.The results showed that because the downdraft produced by a helicopter rotor increased the penetrability of crops,there is a higher deposition on the upper layer and the under layer than the traditional spraying.The average deposition on the upper layer accounts for 28% of the total spraying,the deposition on the under layer accounts for 26% of the total spraying.The deposition on the under layer takes up 92.8% of the deposition on the upper layer.Droplets drift data showed that the drift of non-target area took up 12.9% of the total liquid spray.The 90% drifting droplets were located within a range of 8 m of the target area;the drift quantity was almost zero at a distance of 50 m away from the treated area.展开更多
为研究不同侧风和静电电压对静电喷雾雾滴飘移的影响规律,设计不同侧风(恒速风1、2、4 m/s及0~4 m/s变化的模拟自然风)及静电电压(0,2,4,6,8 k V),进行喷杆式静电喷雾机的雾滴飘移试验,测定不同静电电压下的雾滴粒径与荷质比,并对比分...为研究不同侧风和静电电压对静电喷雾雾滴飘移的影响规律,设计不同侧风(恒速风1、2、4 m/s及0~4 m/s变化的模拟自然风)及静电电压(0,2,4,6,8 k V),进行喷杆式静电喷雾机的雾滴飘移试验,测定不同静电电压下的雾滴粒径与荷质比,并对比分析雾滴飘移质量中心距和飘失率。结果表明:随着静电电压的增大,雾滴粒径减小,雾滴荷质比增大,0~8 k V电压下电极干燥和电极打湿对雾滴荷质比没有显著影响。在侧风风速为1 m/s时,0~8 k V静电喷雾的雾滴飘移中心距小于0.55 m,雾滴飘失率低于15%。在侧风风速2 m/s时,非静电喷雾的雾滴飘失率为11.9%,6~8 k V静电喷雾的雾滴飘失率超过20%,其中静电电压8 k V的雾滴飘失率(23.9%)比非静电喷雾增加100.8%。在侧风风速4 m/s时,4~8 k V静电喷雾的雾滴飘移中心距在0.9 m以上,雾滴飘失率在30%以上,其中静电电压8 k V下的雾滴飘移中心距为967.2 mm比非静电喷雾下增加了13.7%,雾滴飘失率为35.4%比非静电喷雾下增加了59.5%。相同静电电压下,2 m/s的恒速风和0~4 m/s变化的模拟自然风之间对雾滴飘失率无显著差异。该研究为优化喷雾技术参数和提高雾滴抗飘移的能力提供参考。展开更多
A complex interaction of controllable and uncontrollable factors is involved in aerial application of crop production and protection materials.Although it is difficult to completely characterize spray deposition and d...A complex interaction of controllable and uncontrollable factors is involved in aerial application of crop production and protection materials.Although it is difficult to completely characterize spray deposition and drift,these important factors can be estimated with appropriate sampling protocol and analysis.Application height is an important variable influencing off-target spray drift,but this variable has not been easily measured or logged.A custom-configured aircraft-mounted laser with logging capabilities makes this possible.This study was designed to investigate droplet size and deposition characteristics of a low drift CP flat-fan nozzle at application altitudes 3.7 m,4.9 m,and 6.1 m.In the study,CP flat-fan nozzles were set to a downward angle of 30 degrees applying a mixture of water,Syl-Tac®adjuvant,and Rubidium Chloride(RbCl)tracer at a 28.5 L/ha application rate.Spray droplets were collected using water sensitive paper(WSP)cards placed in the spray swath.Mylar sheets were also placed in the swath and downwind for drift sampling.Statistical analysis indicated that median droplet diameter as determined by WSP in the spray swath was not significantly influenced by spray application height.Similarly,statistical analysis also indicated that concentration of RbCl tracer from Mylar samplers in the spray swath was not significantly influenced by application height.Application height had a significant effect on spray deposition from drift samplers,along with wind direction and relative humidity.Final results for drift samplers may have been influenced by shifts in wind direction that altered the relationship between orientation of samplers and wind.展开更多
Droplet drift wastes pesticide,pollutes the environment,and has become one of the focus issues of agricultural crop protection.Electrostatic spray technology reduces drift to a certain degree.In order to investigate t...Droplet drift wastes pesticide,pollutes the environment,and has become one of the focus issues of agricultural crop protection.Electrostatic spray technology reduces drift to a certain degree.In order to investigate the droplet drift pattern of a conical electrostatic nozzle,the droplet drift mass center distance was defined as an experimental index and used to conduct experimental wind tunnel studies on droplet drift.A mathematical model of the droplet drift mass center distance versus electrostatic voltage and wind speed was created via the regression method.The test results showed that the electrostatic voltage had an insignificant effect on droplet drift,the wind speed and its interaction with the electrostatic voltage had significant effects on droplet drift.When the wind speed was less than 3 m/s and stable,the crop adsorbability of a droplet had a dominant effect on the droplet drift;the droplet drift decreased with the increase of electrostatic voltage.When the wind speed exceeded 3 m/s and was stable,the reduced droplet particle size had a dominant effect on droplet drift,where droplet drift increased as the electrostatic voltage increased.When the wind speed was 0 m/s and the electrostatic voltage was 12 kV,the minimum droplet drift mass center distance was 35.5 mm,which was 56 mm less than that of conventional nozzle droplet drift.Therefore,a conical electrostatic nozzle is inapplicable for operation in an environment where wind speeds exceed 3 m/s.This study provides a reference for optimizing operational parameters of conical electrostatic nozzles and improving the anti-drift capability of droplets.展开更多
基金Special Fund for Agro-scientific Research in the Public Interest(201203025)by Ministry of Agriculture,Chinathe National High Technology Research and Development Program of China(SS2013AA100303).
文摘Field trials were performed to evaluate various techniques for measuring spray deposition and aerial drift during spray application to paddy field.The application of a spraying agent containing the fluorescent dye Rhodamine-B was applied by an unmanned aerial vehicle(UAV)which flew at a height of 5 m,a speed of 3 m/s,and the wind speed of 3 m/s.The results showed that because the downdraft produced by a helicopter rotor increased the penetrability of crops,there is a higher deposition on the upper layer and the under layer than the traditional spraying.The average deposition on the upper layer accounts for 28% of the total spraying,the deposition on the under layer accounts for 26% of the total spraying.The deposition on the under layer takes up 92.8% of the deposition on the upper layer.Droplets drift data showed that the drift of non-target area took up 12.9% of the total liquid spray.The 90% drifting droplets were located within a range of 8 m of the target area;the drift quantity was almost zero at a distance of 50 m away from the treated area.
文摘为研究不同侧风和静电电压对静电喷雾雾滴飘移的影响规律,设计不同侧风(恒速风1、2、4 m/s及0~4 m/s变化的模拟自然风)及静电电压(0,2,4,6,8 k V),进行喷杆式静电喷雾机的雾滴飘移试验,测定不同静电电压下的雾滴粒径与荷质比,并对比分析雾滴飘移质量中心距和飘失率。结果表明:随着静电电压的增大,雾滴粒径减小,雾滴荷质比增大,0~8 k V电压下电极干燥和电极打湿对雾滴荷质比没有显著影响。在侧风风速为1 m/s时,0~8 k V静电喷雾的雾滴飘移中心距小于0.55 m,雾滴飘失率低于15%。在侧风风速2 m/s时,非静电喷雾的雾滴飘失率为11.9%,6~8 k V静电喷雾的雾滴飘失率超过20%,其中静电电压8 k V的雾滴飘失率(23.9%)比非静电喷雾增加100.8%。在侧风风速4 m/s时,4~8 k V静电喷雾的雾滴飘移中心距在0.9 m以上,雾滴飘失率在30%以上,其中静电电压8 k V下的雾滴飘移中心距为967.2 mm比非静电喷雾下增加了13.7%,雾滴飘失率为35.4%比非静电喷雾下增加了59.5%。相同静电电压下,2 m/s的恒速风和0~4 m/s变化的模拟自然风之间对雾滴飘失率无显著差异。该研究为优化喷雾技术参数和提高雾滴抗飘移的能力提供参考。
文摘A complex interaction of controllable and uncontrollable factors is involved in aerial application of crop production and protection materials.Although it is difficult to completely characterize spray deposition and drift,these important factors can be estimated with appropriate sampling protocol and analysis.Application height is an important variable influencing off-target spray drift,but this variable has not been easily measured or logged.A custom-configured aircraft-mounted laser with logging capabilities makes this possible.This study was designed to investigate droplet size and deposition characteristics of a low drift CP flat-fan nozzle at application altitudes 3.7 m,4.9 m,and 6.1 m.In the study,CP flat-fan nozzles were set to a downward angle of 30 degrees applying a mixture of water,Syl-Tac®adjuvant,and Rubidium Chloride(RbCl)tracer at a 28.5 L/ha application rate.Spray droplets were collected using water sensitive paper(WSP)cards placed in the spray swath.Mylar sheets were also placed in the swath and downwind for drift sampling.Statistical analysis indicated that median droplet diameter as determined by WSP in the spray swath was not significantly influenced by spray application height.Similarly,statistical analysis also indicated that concentration of RbCl tracer from Mylar samplers in the spray swath was not significantly influenced by application height.Application height had a significant effect on spray deposition from drift samplers,along with wind direction and relative humidity.Final results for drift samplers may have been influenced by shifts in wind direction that altered the relationship between orientation of samplers and wind.
基金the National Key Technology R&D Program:Study and demonstration of technology and equipment for the entire cycle of large-scale production of high-quality rice(2014BAD06B01).
文摘Droplet drift wastes pesticide,pollutes the environment,and has become one of the focus issues of agricultural crop protection.Electrostatic spray technology reduces drift to a certain degree.In order to investigate the droplet drift pattern of a conical electrostatic nozzle,the droplet drift mass center distance was defined as an experimental index and used to conduct experimental wind tunnel studies on droplet drift.A mathematical model of the droplet drift mass center distance versus electrostatic voltage and wind speed was created via the regression method.The test results showed that the electrostatic voltage had an insignificant effect on droplet drift,the wind speed and its interaction with the electrostatic voltage had significant effects on droplet drift.When the wind speed was less than 3 m/s and stable,the crop adsorbability of a droplet had a dominant effect on the droplet drift;the droplet drift decreased with the increase of electrostatic voltage.When the wind speed exceeded 3 m/s and was stable,the reduced droplet particle size had a dominant effect on droplet drift,where droplet drift increased as the electrostatic voltage increased.When the wind speed was 0 m/s and the electrostatic voltage was 12 kV,the minimum droplet drift mass center distance was 35.5 mm,which was 56 mm less than that of conventional nozzle droplet drift.Therefore,a conical electrostatic nozzle is inapplicable for operation in an environment where wind speeds exceed 3 m/s.This study provides a reference for optimizing operational parameters of conical electrostatic nozzles and improving the anti-drift capability of droplets.
