News

In recent years, with the promotion of large-scale land planting and the national pesticide zero growth policy, efficient plant protection equipment such as ground efficient wide spray bar spray, orchard mist sprayer and plant protection UAV have developed rapidly. However, due to the immature application technology and the lack of research on special chemicals, the phenomenon of pesticide drift is prominent in the process of low volume and ultra-low volume spray, and crop pesticide accidents occur frequently, which seriously affects environmental pollution.
In order to effectively control the drift of pesticides, promote the research, development and promotion of new anti drift agents, additives and new pesticide application machines and tools, and standardize the scientific development of efficient plant protection operations, recently, the second international academic seminar on drift loss and anti drift technology, sponsored by the Research Center of Pharmaceutical Machinery and Application Technology of China Agricultural University, China Pesticide Industry Association and China Association for Plant Protection, was held in Beijing. The meeting discussed the "droplet drift law and factors affecting drift, new anti drift and anti drift technology, droplet drift detection technology, management and regulations of drift control, and anti drift and anti drift technology of plant protection UAV".
"Advanced plant protection machinery and equipment and pesticide application technology are not only one of the important measures to ensure the high and stable yield of crops, but also an important means to promote the reduction of application of pesticides and fertilizers, improve the quality and safety of agricultural products, reduce rural pollution and achieve green agricultural development." Gong Yuanshi, vice president of China Agricultural University, said in his speech that because of China's vast territory and diverse crop types, the demand for high-quality and safe pesticides, plant protection machinery and pesticide application technology is also diversified, which requires enterprises to develop products according to their own characteristics and crop types, and also be good at absorbing new research results and learning from advanced and developed countries.
Under the framework of comprehensive management and green prevention and control, how to effectively achieve the precision of chemical prevention and control is the focus and key point to continuously promote the negative growth of pesticide use. The research on drift loss and anti drift loss technology of pesticide use provides key support for this. Especially in recent years, with the rise and popularity of plant protection UAVs, the drift problem associated with low capacity and ultra-low capacity spray technology has become more prominent. It is an important factor that can not be ignored to affect the target crop control efficiency, bring non target crop harm, and cause ecological environment pollution. It needs comprehensive support of policies, regulations, standards, procedures, and product technology to comprehensively discuss and actively promote.
"Controlling pesticide drift is an important measure to achieve accurate pesticide application and improve pesticide utilization.", The use of pesticides affects the quality, safety and effective supply of agricultural products. Practice has proved that poor use of pesticides will affect the consumer confidence of the public, and then affect the income of growers, which will be transmitted to the entire pesticide industry, causing serious impact. Therefore, in promoting the scientific use of pesticide safety, management departments, scientific research institutions, production enterprises, farmers and the public are a community of shared destiny, We need to unify our thinking and understanding, share responsibilities and rationally promote our work. Since 2015, the Ministry of Agriculture and Rural Affairs has been vigorously promoting the green prevention and control of pests and diseases, the rule of unified prevention and control, the substitution of efficient medical equipment and the promotion of precision application technology, improving the level of scientific drug use, improving the efficiency of pesticide utilization, and achieving the new goal of negative growth in pesticide use.
Ecological, safe and efficient precision agriculture is the future direction of development. The development and application of plant protection UAVs, spray bar spray and orchard spray are of great significance to the future advancement of agricultural modernization, meeting China's urgent need for new and efficient agricultural technology and equipment in the process of agricultural modernization. In particular, plant protection UAVs save water and labor, and are widely cited for their separation from human beings. There are many problems in the development process, such as re spraying, missed spraying, pesticide damage and other problems caused by drift, and drift prevention technology has gradually become a hot spot.
According to statistics, there are about 480000 spray bar spray (including traction type and self-propelled type) in the national market at present, the pesticide deposition rate is 55%~60%, and the spray width can reach 32 meters. They are widely used in dry and paddy fields. There are about 600000 stretcher powered spray in the market, and the pesticide deposition rate is 15%~30%, mainly concentrated in fruit trees and vegetable production areas. The plant protection UAV market has more than 30000 aircrafts, and the pesticide deposition rate is 50%~60%, mainly wheat and rice. It is estimated that the population will exceed 50000 in 2019. There are about 400 navigable plant protection aircraft (helicopters, fixed wings), and the pesticide deposition rate is 40%~60%. The operation object is mainly rice. The manual backpack spray has been replaced by the electric spray, which has a large market share and is still the choice of small farmers and yard planting.
"China uses 300000 tons of pesticides a year, but only 30% of them are deposited on crops, and 70% of them are lost to the environment. In fact, not only plant protection UAVs, but also ground machinery and aerial machinery are facing the problem of pesticide loss!" Professor He Xiongkui, director of the Research Center for Pharmaceutical Machinery and Application Technology of China Agricultural University, pointed out that pesticide drift is not a new topic. In fact, as early as the 1970s/80s of the last century, research on anti drift technology has been started abroad, and China has made significant progress in the past decade. To reduce the loss of pesticides, the research and development of new drugs and equipment is the key, the goal is to improve the utilization rate of droplet deposition, and the establishment and training of professional teams are the basis. Practice has proved that the spread and application of anti drift nozzles can reduce drift loss by more than 95%.
In view of the problems existing in the current market application of plant protection machinery, from ground spray bar spray to general aviation and plant protection UAV, there are serious drift problems. The big problem of the spray bar spray is that it is difficult to integrate agricultural machinery and agronomy. Due to the heavy weight of the machine, the paddy field collapses seriously when spraying pesticide, and the crop pressure loss rate is 3 ‰~10 ‰, so it is difficult to transfer. The big problem of the pneumatic spray is that it is difficult to control the spray volume, and it can be hit wherever it goes. In addition, because orchards are mainly concentrated in mountainous and hilly areas, and most of them are densely planted, the market share is very low. From the technical level, the spray system of plant protection UAV is still dominated by ground machinery. The spraying uniformity variation coefficient of major manufacturers in China is not less than 40%. The impact of pesticide drift on bees, aquatic organisms, silkworms and other targets has not yet been evaluated.
In view of the current hot market of plant protection UAVs, He Xiongkui said that currently China's manual spray still accounts for 72% of the market share, and plant protection UAVs are a good alternative. From the perspective of cost, maintenance, etc., the future must be the world of electric multi rotor. With the deepening of research, the oil powered aircraft has shown great application potential in cash crops. If the problem of drift loss cannot be solved, it will become a big short board limiting the development of plant protection UAV. Unfortunately, the current research and development of unmanned aerial vehicles (UAVs) has entered a misunderstanding. More people study remote control systems than spray systems. There are almost no professional sprinklers on UAVs, including how to combine wind fields and dosage forms to reduce drift loss and truly achieve low volume medication.
How strict is the control of pesticide loss abroad? In the United States, as long as the pesticide products are registered for spraying, it is necessary to provide the technical test report of pesticide drift loss reviewed by the EPA of the United States. The compensation for this information alone is more than 1 million dollars. Ma Guangming, the pesticide management expert of the former California Environmental Protection Agency, said that in the US EPA review of the pesticide drift loss technical test report, the drift loss rate of pesticides will be divided into four grades with standard test nozzles, and it is stipulated that only pesticide products with a potential spray drift loss rate of 25%~50% can be registered for flight prevention. Drift and residue are two major concerns of UAV flight defense, and these two problems still need to be solved from the four aspects of "human, machine, agent and technology". Ma Guangming believes that the advantage of UAV is that it has pioneered China's productive agricultural clothing and added a new tool to plant protection technology. In the future, the application scope of UAV will be expanded to spraying, fertilization, sowing, monitoring, remote sensing, yield measurement, pest forecasting, insurance and other fields.
In terms of some key technical standards for the application of plant protection UAVs, when UAVs are used to kill insects and germicides, the flight height should not exceed 2 meters, and the dosage per mu should not be less than 1 liter. When they are used to kill herbicides, regulators, and defoliants, the height should not exceed 1 meter. The lower the flight, the better the effect, and the dosage should not be less than 3 liters.
In view of the future development direction of plant protection machinery, the improvement potential of backpack spray is not large, and the problem of sprayer is mainly solved; The boom spray is the mainstream development direction in the future, which will be developed from the traction (suspension) type to the self-propelled type, focusing on solving the problems of driving speed and spraying stability. The problem of drift loss can be solved by installing anti drift wind curtains, and the problem of difficult promotion of ground machinery can be solved by planting standardization and field driving speed. Aviation plant protection is the integration of "human, aircraft, agent and technology" technologies. Whether aviation plant protection can develop healthily or not, the application technology is the core. The practice of "emphasizing flight training and ignoring plant protection technology" must be changed, and both flight skills and plant protection technology must be included in the training. In the future, the three-dimensional and standardized pest control of "air+ground" is the key to achieve pesticide reduction and green agricultural development.