TY - JOUR

T1 - Coupling of interfacial soil properties and bio-hydrological processes

T2 - The Flow Cell Concept

AU - Krueger, Jiem

AU - Heitkötter, Julian

AU - Leue, Martin

AU - Schlüter, Steffen

AU - Vogel, Hans-Jörg

AU - Marschner, Bernd

AU - Bachmann, Jörg

N1 - Funding information: The authors like to thank the Deutsche Forschungsgemeinschaft DFG for financial support within the Research Group “SUBSOM”, BA1359/ 604212. We like to thank Martin Volkmann for his technical support during FC construction and Dr. John Maximilian Köhne (Soil Physics Department, UFZ?Halle) for his technical support during radiographical measurements. Also we like to thank Susanne K. Woche for XPS and CA analysis. The authors like to thank the Deutsche Forschungsgemeinschaft DFG for financial support within the Research Group ?SUBSOM?, BA1359/604212. We like to thank Martin Volkmann for his technical support during FC construction and Dr. John Maximilian K?hne (Soil Physics Department, UFZ-Halle) for his technical support during radiographical measurements. Also we like to thank Susanne K. Woche for XPS and CA analysis.

PY - 2018/9/21

Y1 - 2018/9/21

N2 - By applying the newly developed flow cell (FC) concept, this study investigated the impact of small-scale spatial variations (millimetre to centimetre) in organic matter (OM) composition (diffusive reflectance infrared Fourier transform spectroscopy), biological activity (zymography), and wettability (contact angle [CA]) on transport processes (tracer experiments, radiography). Experiments were conducted in five undisturbed soil slices (millimetre apart), consisting of a sandy matrix with an embedded loamy band. In the loamy band increased enzyme activities and OM (10 mm apart) were found compared with the sand matrix, with no interrelations although spatial autocorrelation ranges were up to 7 cm. CAs were increased (0–110°) above the loamy band and were negatively correlated with acid phosphatase. Missing correlations were probably attributed to texture variations between soil slices. A general correlation between CA and C content (bulk) were confirmed. Variability in texture and hydraulic properties led to the formation of heterogeneous flow patterns and probably to heterogeneously distributed interfacial properties. The new FC concept allows process evaluation on the millimetre scale to analyse spatial relations, that is, between small-scale textural changes on transport processes and biological responses. The concept has been proved as a versatile tool to analyse spatial distribution of biological and interfacial soil properties in conjunction with the analysis of complex micro-hydraulic processes for undisturbed soil samples. The concept may be improved by additional nondestructive imaging methods, which is especially challenging for the detection of small-scale textural changes.

AB - By applying the newly developed flow cell (FC) concept, this study investigated the impact of small-scale spatial variations (millimetre to centimetre) in organic matter (OM) composition (diffusive reflectance infrared Fourier transform spectroscopy), biological activity (zymography), and wettability (contact angle [CA]) on transport processes (tracer experiments, radiography). Experiments were conducted in five undisturbed soil slices (millimetre apart), consisting of a sandy matrix with an embedded loamy band. In the loamy band increased enzyme activities and OM (10 mm apart) were found compared with the sand matrix, with no interrelations although spatial autocorrelation ranges were up to 7 cm. CAs were increased (0–110°) above the loamy band and were negatively correlated with acid phosphatase. Missing correlations were probably attributed to texture variations between soil slices. A general correlation between CA and C content (bulk) were confirmed. Variability in texture and hydraulic properties led to the formation of heterogeneous flow patterns and probably to heterogeneously distributed interfacial properties. The new FC concept allows process evaluation on the millimetre scale to analyse spatial relations, that is, between small-scale textural changes on transport processes and biological responses. The concept has been proved as a versatile tool to analyse spatial distribution of biological and interfacial soil properties in conjunction with the analysis of complex micro-hydraulic processes for undisturbed soil samples. The concept may be improved by additional nondestructive imaging methods, which is especially challenging for the detection of small-scale textural changes.

KW - DRIFT spectroscopy

KW - X-ray radiography

KW - extracellular enzyme activity

KW - flow cell

KW - soil water repellency

KW - transport processes

KW - undisturbed soil

UR - http://www.scopus.com/inward/record.url?scp=85052381798&partnerID=8YFLogxK

U2 - 10.1002/eco.2024

DO - 10.1002/eco.2024

M3 - Article

VL - 11

JO - ECOHYDROLOGY

JF - ECOHYDROLOGY

SN - 1936-0584

IS - 6

M1 - e2024

ER -