Examination of soil aggregate structure, chemistry, and microbiology to enhance soil fertility

2017 Fiscal Year Final Research Report

• Project/Area Number: 15KT0036
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Multi-year Fund
• Section: 特設分野
• Research Field: Food Cycle Research
• Research Institution: National Agriculture and Food Research Organization (2016-2017); National Institute for Agro-Environmental Sciences (2015)
• Principal Investigator: Wagai Rota 国立研究開発法人農業・食品産業技術総合研究機構, 農業環境変動研究センター, 上級研究員 (80456748)
• Co-Investigator(Kenkyū-buntansha): 濱村 奈津子 九州大学, 理学研究院, 准教授 (50554466) ; 長尾 眞希 (浅野眞希) 筑波大学, 生命環境科学研究科, その他 (80453538) ; 森泉 美穂子 龍谷大学, 農学部, 准教授 (10220039)
• Co-Investigator(Renkei-kenkyūsha): MORONO Yuki 国立研究開発法人海洋研究開発機構, 高知コア研究所, グループリーダー代理 (30421845)
• Research Collaborator: URAMOTO Go-Ichiro (70612901)
• Project Period (FY): 2015-07-10 – 2018-03-31
• Keywords: 土壌有機物 / 有機炭素 / 有機窒素 / 団粒構造 / 微生物群集組成 / 農地管理 / 保全型農業 / トモグラフィー

Outline of Final Research Achievements

Long-term soil conservation practices (compost addition, no-tillage) led to the accumulation of organic matter (OM) including organic N in the aggregates of intermediate density range as well as in low-density fraction. Despite characterization of alkali-soluble organic N, the chemical nature of the accreted N remained unclear. Using synchrotron-based X-ray computer tomography with Os staining of OM, we developed a method to visualize OM localization within macroaggregates at spatial resolution of 0.5 micron. Upon the decline in OM input to soil, the proportion of OM exposed to pores within macroaggregates declined and that of OM attached to solids increased. The approached developed here would make it possible to examine material transport, OM dynamics and microbial activity from the common physical framework of 3-D aggregate structure.

Free Research Field

土壌科学、生物地球化学