2025 年 63 巻 2 号 p. 76-82
The disposal of large quantities of digested slurry from biogas system plants presents a significant challenge. One potential solution is to encourage its use as a liquid fertilizer in nearby upland farms. This study examines the manuring of organic matter and chemical fertilization in upland farming in Hokkaido’s Tocachi Upland areas. Historically, dairy farms in these areas have supplied upland farms with compost and manure slurry, which contribute to fertilization efforts. Therefore, this study analyzes the actual inputs of digested slurry, compost, manure slurry, and chemical fertilizers in upland farms in the area considering that these fertilizing efforts were limited to the nitrogen component. To evaluate the impact of digested slurry as a substitute for chemical fertilizers in upland farming, manuring compost and manure slurry must be considered in upland farming.