Reactivity of organic carbon on earth surface: an examination of common mechnisms between soils and sediments(Fostering Joint International Research)

• Project/Area Number: 15KK0028
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: National Agriculture and Food Research Organization (2016-2018); National Institute for Agro-Environmental Sciences (2015)
• Principal Investigator: Rota Wagai 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)
• Research Collaborator: Chenu Claire フランス国立農学研究所, 農業生態系部門, 教授 ; Peth Stephan カッセル大学, 土壌科学科, 教授 ; Nunan Naoise 環境科学研究所, 国立生態学, 上席研究員
• Project Period (FY): 2016 – 2018
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥13,000,000 (Direct Cost: ¥10,000,000、Indirect Cost: ¥3,000,000)
• Keywords: 炭素貯留 / 地球温暖化 / 鉱物・有機物相互作用 / 団粒 / 土壌有機物 / 団粒構造 / 有機物・鉱物相互作用 / X線コンピュータートモグラフィー / 土壌科学 / 有機物安定化 / 炭素隔離 / 土壌炭素 / 生物地球化学 / 土壌微生物 / 炭素循環 / 土壌 / 堆積物 / 物質循環 / 陸上生態系

Outline of Final Research Achievements

Interaction with mineral is a major mechanism of organic matter (OM) stabilization in soils and sediments. However, the mode of interaction depends strongly on the spatial scale, which creates a big challenge in our understanding of OM-mineral interaction. At a smallest scale, we conducted incubation experiments using model bacteria and model mineral particles to gain basic information on their interaction. At a large scale, we focused on water-stable aggregate which is the outcome of OM-mineral interactions at smaller scales and developed an approach to examine 3-D inter-relationship between pore, mineral, and OM through aggregate fixation/staining of C, X-ray microCT measurement, and a series of image analyses. We also attempted to make a functional linkage between micro- and macro-scale interaction of OM and mineral.

Academic Significance and Societal Importance of the Research Achievements

●作物の持続的な生産には土壌有機物の維持・増進が基盤となる。また、土壌有機物の増加は、大気中の炭素を隔離するため、地球温暖化の緩和策として世界的に期待されている。鉱物粒子と有機物の集合体は階層構造を持つが、その低次構造から高次構造の形成および高次構造の崩壊を予測し制御できるようになれば、劣化した農地や生態系の保全、肥沃度管理、温室効果ガス放出の削減といった社会ニーズに対応できるようになる。
●既存の土壌炭素モデルでは、土壌構造と水・炭素動態は関連づけられていない。本研究成果は、これを可能にする重要なステップであり、次世代の物質循環モデル開発に必須の知見と考える。

Research Products

• [Int'l Joint Research] パリ国立農業学校／国立農学研究所 農業生態系部門(フランス) (2017)
  • Year and Date: 2017-08-30
• [Journal Article] An improved method to identify osmium-stained organic matter within soil aggregate structure by electron microscopy and synchrotron X-ray micro-computed tomography (2019)
  • Author(s): Miwa Arai, Go-Ichiro Uramoto, Maki Asano, Katsuyuki Uematsu, KentaroUesugi, Akihisa Takeuchi, Yuki Morono, Rota Wagai
  • Journal Title: Soil and Tillage Research Volume: 191 Pages: 275-281
  • DOI: 10.1016/j.still.2019.04.010
  • Peer Reviewed
• [Journal Article] In search of a binding agent: nano-scale evidence of preferential carbon associations with poorly-crystalline mineral phases in physically-stable-clay-sized aggregates (2018)
  • Author(s): Asano, M., Wagai, R., Yamaguchi, N., Takeichi, Y., Maeda, M., Suga, H., Takahashi, Y.
  • Journal Title: Soil Systems Volume: 2(2) Issue: 2 Pages: 32-32
  • DOI: 10.3390/soilsystems2020032
  • NAID: 120007133044
  • Peer Reviewed / Open Access
• [Presentation] Quantifying aggregate structure of contrasting carbon levels in Andisol by synchrotron-based X-ray microtomography (2018)
  • Author(s): Arai M, Uramoto G-I, Asano M, Uematsu K, Uesugi K, Takeuchi A, Morono Y, Wagai R
  • Organizer: European Geoscience Union General Assembly 2018
  • Int'l Joint Research
• [Presentation] Facing pore or solid matrix? Location of organic matter in macroaggregates from two volcanic soils of contrasting C levels, examined by synchrotron-based X-ray CT (2018)
  • Author(s): Arai M, Uramoto G-I, Asano M, Uematsu K, Uesugi K, Takeuchi A, Morono Y, Wagai R
  • Organizer: Workshop on “Elucidating microbial processes in soils and sediments: Microscale measurements and modeling”
  • Int'l Joint Research
• [Presentation] 団粒の三次元構造内部の 間隙および有機物の空間分布の特徴： 放射光源を利用したX線CT法とOs染色法の応用 (2018)
  • Author(s): 荒井見和、浦本豪一郎、浅野眞希、諸野祐樹、上杉健太郎、 竹内晃久、岩崎亘典、和穎朗太
  • Organizer: 日本土壌肥料学会2018年神奈川大会
• [Presentation] Isotopic enrichment of C-13 and N-15 with older radiocarbon age for the organo-mineral aggregates from low- to higherdensity soil particles: evidence of mineral protection? (2018)
  • Author(s): Rota Wagai, Masako Kajiura, Maki Asano, Yudzuru Inoue
  • Organizer: European Geosciences Union General Assembly 2018
  • Int'l Joint Research
• [Presentation] Binding agents for aggregation in some Andisols: organic vs. inorganic binders (2017)
  • Author(s): Rota Wagai, Maki Asano, Masako Kajiura
  • Organizer: Workshop on Formation, Properties and Function of Soil Microaggregates, Munich, Germany
  • Int'l Joint Research / Invited