In recent years, advanced agricultural technology continues to develop rapidly, where the voice of farmers is often not taken into consideration. Therefore, it is important to consider the relationship between agricultural technology and farmers’ agency. This paper focuses on the agency of farmers and their use of agricultural technology and investigates how the relationship between pesticide use in rice cultivation and the farmer’s decision-making has changed.
　　　In a case study, this paper focuses on the Reduced-Pesticide Movement which started in Fukuoka prefecture in the late 1970s. This movement centered on reclaiming the agency of farmers in choosing whether or not to reduce pesticide use in rice paddy fields. The interviews were conducted to several farmers actively involved in the movement and agricultural extension officers related to rice production. Drawing from the social shaping of technology approach, this paper analyzed the trajectory of this movement by mapping out the various interactions among different players, materials, and structural constraints.
　　　In the post war era, many farmers lacked knowledge on pest management and were dependent on extension officers who advised strict pesticide application schedules. In the beginning of reduced-pestiside movement, the Mushimiban (a tool for observing insects) was created to allow farmers to make their own decision in regards to pesticide application. In addition, changes in Japan’s rice policy promoted the production of reduced-pesticide rice, and eventually resulted in the development of reduced-pesticide brand. Previously, farmers believed that using pesticide in the rice farming was inevitable. After the experience of movement for reducing pesticide, some farmers began to produce organic rice, while other farmers used pesticides depending on the unique conditions of their paddy fields.