Experimental Study On The Distribution Regularity Of Thrush 510G Large Fixed-wing Aircraft On Soybean Plants

Aviation plant protection field of China shows a thriving scene with the rapid development of agricultural aviation technology in recent years.However,the focus of the society is mainly on the development and experimental study of plant protection unmanned aerial vehicles.There are a few studies on large-scale plant protection aircraft.China's northeast,Xinjiang and other large farming areas are suitable for the large-scale plant protection aircraft.It is very necessary to study the applicability of China's large-scale plant protection aircraft and spraying equipment imported from abroad mainly.The effect of aviation plant protection is directly reflected by the droplet distribution deposited on the crop target.Therefore,this paper aims at studying on distribution regularity of droplet in the crop canopy plant,canopy vertical face and three meteorological conditions by doing a experiment in soybeans using the introduction of the world's advanced models-Thrush510 G.The water droplets were collected using water-sensitive paper as a carrier.The droplet data,including the amount of droplet deposition,deposition density,droplet size and coverage,were used to analyze the droplet distribution in crop canopy and drift zone,canopy vertical surface and three meteorological conditions.The results are as follows:(1)In the drift area of soybean canopy,the distribution of droplet size is affected by drift distance and meteorological conditions.The droplet size decreases linearly with the increase of the drift distance,The linear equation is y =-3.7286 x + 352.65 when the wind speed is 0.6m / s,the temperature is 27.3 ? and the humidity is 43.3%.The smaller the weather velocity is,the smaller the droplet size is in the distal part of the drift zone(30-65 m interval).Try to reduce the number of small droplets to improve the protection of the environment and the surrounding crops;(2)When the relationship between the deposition amount of the upper layer and the deposition amount of the middle layer was studied,it was found that the percentage ofdroplet deposition was 119.1% at 20 m of sampling zone 1 and 148.1% at 0 m of sampling zone 2.That is,the deposition amount of the droplet in the middle layer of the soybean plant was larger than that in the upper layer.The reason for this phenomenon is that the tiny droplets can reach the lower part of the plant in weak wind field.The droplet size distribution in the middle layer of soybeans was consistent with the droplet size distribution in the soybean canopy.Droplet penetration ability within less than 180 ?m of droplet size is weak and higher than 250 ?m of droplet size is strong;(3)Influence of meteorological conditions on droplet deposition.In the deposition area,The coefficient of variation of droplet density distribution was 43.75%,40.05% and34.05%,respectively,which indicated that the uniformity of droplet density distribution decreased with the increase of wind speed..In the drift area,The droplet size is smaller in low wind speed than that in high wind speed in the case of the same drift distance.The smaller the external wind speed,the smaller the droplet density and deposition in the drift zone,This is because when the external wind speed is small,the force of the wind to the droplets is small and the acceleration of the droplets is small,so the droplets drift closer.The percentage of droplet penetration and its coefficient of variation are negatively correlated with the external wind speed,indicating that the smaller the external wind speed,the greater the droplet penetration ability,the worse the distribution uniformity of the droplet penetration ability at the sampling point.(4)Meteorological conditions affect the amount of droplet deposition.,the total deposition of droplets in the three tests were 6.110 ?l,4.010 ?l and 3.623 ?l in the deposition area respectively.The total deposition reduced with the decrease of wind speed.The percentages of droplet deposition were 50.6%,60.2% 66.7%.The smaller the wind speed was,the droplets were easier to pass through the canopy.