On-farm experimentation (OFE) is increasing worldwide. Appropriate OFE procedures may differ depending on the characteristics and circumstances surrounding farms, such as climate, field conditions, farm size, degree of agricultural digitalization, and a farmer’s socioeconomic background. This study aims to guide the future development of OFE in Japanese grain farming by examining the experimental setup, data analysis, and farmers’ activities within their socioeconomic and institutional communication and learning networks. The results of this typical OFE case study, which estimates a field’s economically-optimal fertilizer variable-rate application map for winter wheat production, are reported. The outcomes of the case study, which are intended to guide the direction of OFE development in Japan, were used as reference materials for a survey taken while interviewing farmers who had never been involved in OFE. Farmers’ answers showed that the economic return of site-specific management depends on farm and field size and exhibits economies of scale. A very high share of the profit increases provided by OFE data came from improvements in field-specific uniform rate management, not from within-field site-specific management. The interviews revealed that farmers open to OFE are more interested in increasing rice crop quality to earn price premiums than in increasing yield. Increased engagement with farmers in conducting OFEs could play a key role not only in generating data to guide farmers’ input management but also in fostering farmer collaboration to develop marketing strategies. This study is the first to propose future orientations of OFE research that target typical moderately-sized Japanese grain farms.

世界范围内的农场试验 (OFE) 正在增加。适当的 OFE 程序可能因农场周围的特征和环境而异，例如气候、田地条件、农场规模、农业数字化程度和农民的社会经济背景。本研究旨在通过检查实验设置、数据分析以及农民在其社会经济和制度交流和学习网络中的活动，指导日本粮食农业中 OFE 的未来发展。报道了这个典型的 OFE 案例研究的结果，该研究估计了一个田地的冬小麦生产的经济最佳肥料变量施用图。旨在指导日本 OFE 发展方向的案例研究成果，被用作采访从未参与 OFE 的农民时进行的调查的参考资料。农民的回答表明，定点管理的经济回报取决于农场和田地的规模，并表现出规模经济。OFE 数据提供的利润增长中很大一部分来自于特定领域统一费率管理的改进，而不是来自领域内特定站点的管理。访谈显示，对 OFE 持开放态度的农民更感兴趣的是提高水稻作物质量以赚取价格溢价，而不是提高产量。增加农民参与开展 OFE 不仅可以在生成数据以指导农民的投入管理方面发挥关键作用，而且可以在促进农民合作制定营销策略方面发挥关键作用。