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Titel |
Nature of water molecular bridging of the soil organic matter |
VerfasserIn |
Jiri Kucerik, Christian Siewert, Claudia Quilesfogel-Esparza, Gabriele E. Schaumann |
Konferenz |
EGU General Assembly 2014
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 16 (2014) |
Datensatznummer |
250089536
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Publikation (Nr.) |
EGU/EGU2014-3741.pdf |
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Zusammenfassung |
Soil is a complex anisotropic and porous system consisting of both inorganic and organic
parts, air and water, inhabited and successively transformed by soil biota. Processes of soil
formation are influenced by several factors. Among the most important factors
belong the inorganic and organic input materials, which are mixed and transformed
during soil formation. As a result, specific interactions and interrelationships develop
between soil compartments. Although, they are important for soil function and its
stability, they are still not well understood. This work deals with water molecule
bridges (WaMB), as one of those interactions, and their relation to organic matter
functioning.
Differential scanning calorimetry (DSC) belongs to the family of methods of thermal
analysis, i.e. it uses heat as a probe of the sample’s nature. In soil science, the application of
this common method is quite rare. In our previous works, DSC revealed a physical
stabilization of organic matter segments in soils by development of WaMB. Results suggested
the development of those bridges at ambient temperature accompanied with condensation of
water into small nanodroplets. In another work, we found out that water, evaporating at the
same temperature as WaMB transition occurs, correlates with the activity of soil
microorganisms measured via CO2respiration.
In this work, the enthalpy and kinetic parameters of water evaporation are studied in two
kinds of soil: in clay-rich chernozem soils originating from Siberia and a histosol collected in
Germany. We discuss the details of application of DSC, experimental arrangement and
advantages and disadvantages of this approach. It is shown that enthalpy of evaporation can
be used for understanding the nature of water binding in soils with well-developed
aggregates. In contrast, the evaporation of water from histosol, without a typical soil
texture, is more complicated because of diffusion processes. Further, the connection
between enthalpy of evaporation and soil microbiological activity is discussed. |
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