Article All rights reserved
refereed
published

Selective transport and retention of organic matter and bacteria shapes initial pedogenesis in artificial soil - A two-layer column study

Affiliation
Friedrich Schiller University Jena, Institute of Geosciences, Department of Hydrogeology, Burgweg 11, D-07749 Jena, Germany
Lehmann, Katharina;
Affiliation
Friedrich Schiller University Jena, Institute of Geosciences, Department of Hydrogeology, Burgweg 11, D-07749 Jena, Germany
Schaefer, Sabine;
GND
1014430453
Affiliation
Julius Kühn-Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Brunswick, Germany
Babin, Doreen;
Affiliation
Helmholtz Centre for Environmental Research - UFZ Halle, Department of Soil System Sciences, Theodor-Lieser-Strasse 4, D-06120 Halle, Germany
Köhne, John Maximilian;
ORCID
0000-0002-3140-9058
Affiliation
Helmholtz Centre for Environmental Research - UFZ Halle, Department of Soil System Sciences, Theodor-Lieser-Strasse 4, D-06120 Halle, Germany
Schlüter, Steffen;
GND
1058967878
Affiliation
Julius Kühn-Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Brunswick, Germany
Smalla, Kornelia;
Affiliation
Helmholtz Centre for Environmental Research - UFZ Halle, Department of Soil System Sciences, Theodor-Lieser-Strasse 4, D-06120 Halle, Germany
Vogel, Hans-Jörg;
Affiliation
Friedrich Schiller University Jena, Institute of Geosciences, Department of Hydrogeology, Burgweg 11, D-07749 Jena, Germany
Totsche, Kai Uwe

Organic particles including microorganisms are a significant fraction of the mobile organic matter (MOM) pool that contributes to initial pedogenesis. Still, the dynamics and the interplay of the multitude of processes that control the mobilization, transport, and retention of MOM are vastly unclear. We studied this interplay using an ‘artificial soil’ as model for a young, unstructured soil with defined initial composition employing a novel twolayer column experiment. The upstream layer was composed of a mixture of well-defined mineral phases, a sterile organic matter source and a diverse, natural microbial inoculant mimicking an organic-rich topsoil. The downstream layer, mimicking the subsoil, was composed of the mineral phases, only. Columns were run under water-unsaturated flow conditions with multiple flow interruptions to reflect natural flow regimes and to detect possible non-equilibrium processes. Pore system changes caused by flow were inspected by scanning electron microscopy and computed micro-tomography. MOM-related physicochemical effluent parameters and bacterial community diversity and abundance were assessed by molecular analysis of the effluent and the solid phase obtained after the long-term irrigation experiment (75 d). Tomographic data showed homogeneous packing of the fine-grained media (sandy loam). During flow, the initially single-grain structured artificial soil showed no connected macropores. In total, 6% of the initial top layer organic matter was mobile. The release and transport of particulate (1.2%) and dissolved organic matter (4.8%) including bacteria were controlled by non-equilibrium conditions. Bacterial cells were released and selectively transported to downstream layer resulting in a depthdependent and selective establishment of bacterial communities in the previously sterile artificial soil. This study underlines the importance of bacterial transport from the surface or topsoil for colonization and maturation of downstream compartments. This initial colonization of pristine surfaces is the major step in forming biogeochemical interfaces - the prominent locations of intensive biological activity and element turnover that seem to play a major role for the functioning of soil.

Files

Cite

Citation style:
Could not load citation form.

Access Statistic

Total:
Downloads:
Abtractviews:
Last 12 Month:
Downloads:
Abtractviews:

Rights

License Holder: © 2018 Elsevier B.V.

Use and reproduction:
All rights reserved