Pesticide spraying using agricultural drones shown to be more efficient than existing technologies

The lecturer Seo Yuna and the graduate student Shotaro Umeda of the Department of Industrial Administration, Faculty of Science and Technology, Tokyo University of Science compared the cost, working capacity, and management efficiency of agricultural drones, which are essential tools for realizing smart agriculture, with those of existing technologies for pest management in rice paddy fields. They successfully demonstrated the effectiveness of agricultural drones. Experiments on smart agricultural technologies are currently underway in farm settings; hence, there is a growing need to evaluate the effects of introducing such technologies. In 2016, agricultural drones used for pesticide spraying covered 684 ha of cropland area; by 2018, their coverage had expanded rapidly to approximately 31020 ha, i.e., a 45-fold increase in coverage.

In their study, to clarify the performance and cost effectiveness of drone use for spraying, the researchers investigated the cost, working capacity, and management efficiency associated with three modes of delivery--a boom sprayer attached to a tractor, a radio-controlled helicopter, and an agricultural drone. The study was conducted in conditions that corresponded with actual agricultural conditions in Japan, and the pesticide was sprayed twice a year. A total of 21 scenarios, combining three spraying methods and seven different sizes of farmland (between 0.5 and 30 ha) were prepared. The relative management efficiency among farms was evaluated using data envelopment analysis (DEA) based on an input-oriented model. No large difference in cost relative to arable area was observed between agricultural drones and boom sprayers; it was estimated that the cost for 3-5 ha of arable land was approximately ¥400,000. Some worry that the relatively high maintenance and repair costs may hamper the introduction of agricultural drones. However, irrespective of arable area, radio-controlled helicopters have a fixed cost. This cost is nine times higher than that of agricultural drones, owing to operating personnel (3 people are required) and procurement expenses.

When the duration of the operation was set at 14 days, working capacity was 135 ha for agricultural drones, 120 ha for boom sprayers, and 195 ha for radio-controlled helicopters. Evaluation of results by DEA analysis revealed that agricultural drones were more efficient than boom sprayers or radio-controlled helicopters in arable areas of 0.5-5 ha and that both agricultural drones and boom sprayers were more efficient than radio-controlled helicopters in areas covering 10-30 ha. In arable areas covering 10-30 ha, the superiority of agricultural drones to the other methods was not seen. However, improvements in convenience and reductions of cost because of future technological advances and deregulation are anticipated. "In the future, advanced technologies that combine robots with AI and IoT, including automated tractors, self-driving paddy planters, automated water management systems, automated mowers, and harvesting robots, are likely to be introduced into agricultural fields. To accelerate the implementation of smart agriculture, we believe it is necessary to ensure the safety of each new technology, relax the restrictions, and provide bridges of communication between technology suppliers and agriculture industry consumers."