Discussion of the economic benefits of biogas slurry irrigation by analytic hierarchy process (AHP)

[[abstract]]In this study, the benefits of Biogas slurry irrigation on farmland were evaluated in the background of circular economy. Biogas slurry irrigation is a worldwide option to promote sustainable agriculture and the policy of biogas slurry irrigation has been implemented nationally for more than five years in Taiwan. As the result, the number of irrigating households has been increasing year by year. In this study, we implemented a questionnaire to apply a two-by-two comparison question to the same group of respondents and used the analytic hierarchy process (AHP) to evaluate the factors including cost of fertilizer, environmental benefits, food safety benefits and operational costs in order to analyze the benefits of irrigation. Accordingly, the evaluation results show that 31% in fertilizer cost, 26%in environmental benefits, 23% in food safety benefits and 20% in operating costs conform to pairwise comparison matrix consistency results after validation that the fertilizer cost which has the highest percentage is the most important issue for farmers. Facing the global climate change and rising raw material prices, farmers will have to pay higher costs for fertilizers in the coming future. Therefore, Biogas slurry substitution is proven to not only solve the problems of chemical fertilizers in environmental damages but also creating a sustainable business model to achieve the circular economy policy encouraged by the government in accordance with the global trend of environmental protection.