Direct evidence for thickening nanoscale organic films at soil biogeochemical interfaces and its relevance to organic matter preservation

The emerging consensus on organic matter (OM) cycling in soil and sediment proposes that a continuum of biological and geochemical processes in the micro-environment controls the fate of OM. However, spatio-temporal observation of the biogeochemical nature and behaviour of OM at the soil-water interfaces (SWIs) is impeded by the heterogonous and opaque nature of their microenvironment. Herein, we used a novel SoilChip method (soil microarrays incubated with a predefined solution) to continuously mimic and trace the OM biogeochemistry at SWIs for 21 days. Combining X-ray photoelectron spectroscopy and ion sputtering on SoilChips, we provided the first direct evidence that a nanoscale organic film with a distinct composition and thickness gradually formed at the SWI within 21 days of cultivation. Although the OM coating on the SWI quickly reached equilibrium within 4 days, the formation of thicker mineral-organic association (MOA, 20-130 nm) and microbial biomass (>130 nm) continued, partially at the cost of the thin MOA (<20 nm). Consistent with the thickening SWI, the bioavailability of nutrients (dissolved organic C and ammonium) decreased gradually over 21 days, which restrained the microbial activities. Collectively, thickening SWIs act as a biogeochemical gate to regulate the bioavailability of specific organic compounds and determine their preservation or microbial mineralization. Further, thickening SWIs in thez-axis direction provide direct structural insight to increase carbon sequestration in soil and sediment. © The Royal Society of Chemistry 2020.

Huang X.1, 2 , Li Y. 1, 3 , Guggenberger G.2, 4 , Kuzyakov Y. 2, 5, 6 , Liu B.-F.1 , Wu J.2
Royal Society of Chemistry
Номер выпуска
  • 1 Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics & Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
  • 2 Key Laboratory of Agro-Ecological Processes in the Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
  • 3 Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
  • 4 Institute of Soil Science, Leibniz University Hannover, Hannover, 30419, Germany
  • 5 Institute of Environmental Sciences, Kazan Federal University, Kazan, 420049, Russian Federation
  • 6 Agro-Technological Institute, RUDN University, Moscow, 117198, Russian Federation
Ключевые слова
Birds; Nanotechnology; Organic compounds; Soil moisture; X ray photoelectron spectroscopy; Biogeochemical interfaces; Carbon sequestration; Dissolved organic C; Microbial activities; Microbial mineralization; Mineral-organic association; Organic matter preservations; Structural insights; Biogeochemistry; bioavailability; biofilm; biogeochemistry; carbon sequestration; nanomaterial; preservation; soil organic matter
Дата создания
Дата изменения
Постоянная ссылка

Другие записи

Galitsyna E.V., Bukharova T.B., Vasilyev A.V., Osidak E.O., Domogatsky S.P., Goldshtein D.V.
IOP Conference Series: Earth and Environmental Science. Institute of Physics Publishing. Том 548. 2020.