Environmental impact of agricultural sprayers used in Japanese rice farming

Abstract

Rice production in Japan faces severe labour shortage; hence, cutting-edge technologies, such as agricultural unmanned aerial vehicle (UAV) sprayers, are being actively considered and tested for installation in agricultural settings by the government. However, the environmental impacts of agricultural UAV sprayers remain unclear. Here, we aimed to assess the environmental performance of agricultural UAV sprayers in pest control during rice production in Japan, by comparing the environmental impact during pest control by using UAV, power, and boom spraying. We performed life cycle analysis with SimaPro 8 using the ReCiPe 2016 Midpoint (H) methodology and carried out sensitivity analyses to estimate the influence of input variables on emissions as a function of operational area. UAV spraying exhibited a lower environmental impact than did boom- and power spraying–attributed to the weight and fuel consumption of boom and power spraying, which increase the environmental impact associated with material production and energy consumption. Pesticide input remained constant, while the required water volumes for pesticide dilution differed among the sprayers. These results suggest the use of lighter and energy-saving machinery to mitigate the environmental impact of pest control in rice production; UAV spraying was found to be a good alternative to conventional methods.