Abstract
Centralized biogas plants for proper treatment and effective utilization of cow liquid manure have contributions to improvement of environmental problem such as odor or lack of capacity in reservoirs and also have secondary effects on saving farmer's labor for transportation and application of manure, and on energy recovery. However, such biogas plants are not still introduced so much because of economic liability for dairy farmers. This study revealed actual situations of improper management of cow liquid manure by questionnaire survey for daily farmers in three regions, Hokkaido, where dairy farming is active. Conjoint analysis revealed that cow farmers consider “improvement of lack of capacity in reservoirs”, “improvement of odor” and “improvement of excessive application of manure” as advantage. The evalution results were also reflected by differences in regional conditions, such as change in the number of cows and existence of crop or vegetable farmers. New strategies for spreading biogas plants are required considering regionally-different dairy farmer's needs for dairy farmers.
