Description: Das Projekt "Micro-scaled hydraulic heterogeneity in subsoils" wird vom Umweltbundesamt gefördert und von Leibniz Universität Hannover, Institut für Bodenkunde durchgeführt. Nutrient and water supply for organisms in soil is strongly affected by the physical and physico-chemical properties of the microenvironment, i.e. pore space topology (pore size, tortuosity, connectivity) and pore surface properties (surface charge, surface energy). Spatial decoupling of biological processes through the physical (spatial) separation of SOM, microorganisms and extracellular enzyme activity is apparently one of the most important factors leading to the protection and stabilization of soil organic matter (SOM) in subsoils. However, it is largely unknown, if physical constraints can explain the very low turnover rates of organic carbon in subsoils. Hence, the objective of P4 is to combine the information from the physical structure of the soil (local bulk density, macropore structure, aggregation, texture gradients) with surface properties of particles or aggregate surfaces to obtain a comprehensive set of physical important parameters. It is the goal to determine how relevant these physical factors in the subsoil are to enforce the hydraulic heterogeneity of the subsoil flow system during wetting and drying. Our hypothesis is that increasing water repellency enforces the moisture pattern heterogeneity caused already by geometrical factors. Pore space heterogeneity will be assessed by the bulk density patterns via x-ray radiography. Local pattern of soil moisture is evaluated by the difference of X-ray signals of dry and wet soil (project partner H.J. Vogel, UFZ Halle). With the innovative combination of three methods (high resolution X-ray radiography, small scale contact angle mapping, both applied to a flow cell shaped sample with undisturbed soil) it will be determined if the impact of water repellency leads to an increase in the hydraulic flow field heterogeneity of the unsaturated sample, i.e. during infiltration events and the following redistribution phase. An interdisciplinary cooperation within the research program is the important link which is realized by using the same flow cell samples to match the spatial patterns of physical, chemical, and biological factors in undisturbed subsoil. This cooperation with respect to spatial pattern analysis will include the analysis of enzyme activities within and outside of flow paths and the spatial distribution of key soil properties (texture, organic carbon, iron oxide content) evaluated by IR mapping. To study dissolved organic matter (DOM) sorption in soils of varying mineral composition and the selective association of DOM with mineral surfaces in context with recognized flow field pattern, we will conduct a central DOM leaching experiment and the coating of iron oxides which are placed inside the flow cell during percolation with marked DOM solution. Overall objective is to elucidate if spatial separation of degrading organisms and enzymes from the substrates may be interconnected with defined physical features of the soil matrix thus explaining subsoil SOM stability and -dynami
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Rochen ? Hannover ? Bodennährstoff ? Eisenoxid ? Röntgenstrahlung ? Schlichtemittel ? Substrat ? Vogel ? Organischer Kohlenstoff ? Biopharmazeutikum ? Humus ? Nährstoff ? Resistenz ? Pflanzensamen ? Anstrich ? Bodeninformation ? Bodenkunde ? Bodenwasser ? Enzym ? Gebäude ? Hydraulik ? Infiltration ? Kartographie ? Karte ? Unterboden ? Mineralboden ? Gebühr ? Sorption ? Rechtsverfahren ? Bewässerung ? Bodenart ? Bodenqualität ? Radiografie ? Bodenlösung ? Bodenorganismen ? Strömungsfeld ? Studie ? Bodenprobe ? Trocknung ? Versorgung ? Bodenuntersuchung ? Wasserprobe ? Wasserversorgung ? Zelle ? Mikroorganismen ? Bodenfeuchte ? Wasser ? Boden ? Chemikalien ? Bauliche Anlage ? Energie ? Perkolation ? Wirkung ? Bodenaufbau ? Abscheidung ? Auslaugung ? Ballungsraum ? Versickerung ? Zusammenarbeit ? Partikel ? Bodenverfestigung ? Mineral ? Feuchtigkeit ? Forschung ? Forschungsprogramm ? Kenngröße ? Organismen ? Gewebe ? Röntgenuntersuchung ? Buchgrundstück ? Fluss [Bewegung] ? Entkopplung ? Gebühr [Abgabe] ? Bemessung ? Vermehrung ?
Region: Lower Saxony
Bounding box: 9.16667° .. 9.16667° x 52.83333° .. 52.83333°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2013-07-10 - 2024-11-29
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