Proposal of regionally available biomass waste compost with useful functions and less environmental impacts based on scientific evaluation of local and indigenous knowledge in Vietnam

2023 Fiscal Year Final Research Report

• Project/Area Number: 20KK0147
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 41:Agricultural economics and rural sociology, agricultural engineering, and related fields
• Research Institution: Okayama University
• Principal Investigator: Maeda Morihiro 岡山大学, 環境生命自然科学学域, 教授 (00355546)
• Co-Investigator(Kenkyū-buntansha): 染谷 孝 佐賀大学, 農学部, 客員研究員 (30154719) ; 赤尾 聡史 同志社大学, 理工学部, 教授 (30448196) ; 中村 真人 国立研究開発法人農業・食品産業技術総合研究機構, 農村工学研究部門, 上級研究員 (60414463) ; 折立 文子 国立研究開発法人農業・食品産業技術総合研究機構, 農村工学研究部門, 主任研究員 (90535303) ; 藤田 睦 国立研究開発法人農業・食品産業技術総合研究機構, 農村工学研究部門, 研究員 (60965903)
• Project Period (FY): 2020-10-27 – 2024-03-31
• Keywords: 嫌気性堆肥 / 窒素循環 / 温室効果ガス / 微生物群集 / 衛生細菌

Outline of Final Research Achievements

In Vietnam, anaerobic fermentation is used to compost livestock waste, and its properties are entirely different from those of aerobic compost in Japan. Because livestock waste is locally increasing yearly, we need to rethink composting methods from a modern perspective. This study aimed to compare the functionality and environmental loadings between anaerobic and aerobic compost, clarify the advantages and disadvantages of local anaerobic compost, and propose the best composting way to increase soil ecosystem services in Vietnam. Through field surveys and on-site composting experiments, we found that Vietnamese compost is not produced under completely anaerobic conditions. Anaerobic compost showed high CH4 emissions during the composting processes. In the final anaerobic compost products, E. coli and salmonella were not detected, and their chemical properties were not essentially different from aerobic one.

Free Research Field

農業農村工学，土壌肥料学

Academic Significance and Societal Importance of the Research Achievements

我が国では家畜ふんを好気条件で堆肥化することに疑念を持たず，肥効評価法とともにその技術体系が作られてきた．一方，嫌気性堆肥は今もベトナムで一般的である．現地特有の慣習や気象条件のもとで作成されており，その作成方法や経緯は現地農家しか知り得ない．嫌気性堆肥の成立条件や機能性，さらには環境負荷に関する多面的な知見が得られれば，堆肥化および炭素・窒素循環に関する研究に新展開が期待できる．日本およびベトナムの若手・中堅研究者が直接顔を合わせた議論を重ねることによって，未来に繋がる信頼関係を築くことができる．