CENTRALIZATION OF DAIRY FARMING FACILITIES COPING WITH BOTH ECONOMIC AND ENVIRONMENTAL SUSTAINABILITY

摘要

Biogasification has been expected to be one of contributor to adequate management of waste biomass and promotion of renewable energy. Technological, economic, social and environmental factors have to be considered when a biogasification system is introduced into a region. In this study, we discuss these factors and identify their structure. Both qualitative and quantitative factors were found in the structure. Based on these considerations, we establish a model that describes the factors surrounding biogasification systems. Several alternatives were proposed to improve the sustainability of such systems, and we evaluated the sustainability of the alternative and suggested the optimum one. As a result of the evaluation, the combination of intensive breeding of cows and biogasification of their excreta was found to guarantee a sustainable level of income without any subsidy. The intensive scale may be as low as 700 cattle, created by the alliance of seven farmers. The other problems, such as stress of cattle in intensive breeding, are future assignment.