Project Details
Projekt
Experimental exploration of denitrification in multiscale porous media and soil
Applicants
Dr. Steffen Schlüter; Professor Dr. Hans-Jörg Vogel
Subject Area
Soil Sciences
Term
from 2016 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 270261188
The aim of this project is to improve our mechanistic understanding of denitrification in undisturbed structured soil. The importance of structural heterogeneity for the onset and dynamics of denitrification was investigated based on artificial porous media and repacked soil during the first project period.Now we experimentally explore denitrification processes in undisturbed soil cores while measuring the porous structure via X-ray microtomography for the identical soil samples. This allows for a direct link between structural features and denitrification. The complex structure is described by a distance distribution from air filled pore space into the water saturated soil matrix which is a function of the macroscopic water content. We hypothesise that this is a meaningful effective property that can be used in an upscaled model to reflect the important structural material properties. Our experiments will demonstrate in how far this is possible. Moreover, we test two critical assumptions required for modelling denitrification at the larger scales. First, the spatial distribution of carbon sources which is visualised in 3D for undisturbed soil using osmium staining and second, the spatial distribution of microorganisms relative to the porous structure. This will provide the required evidence to justify possible simplifying assumptions for modelling. All this will be accomplished in close cooperation with the project partners. The ultimate goal is to predict N emissions in response to atmospheric forcing based on soil structural attributes which can be observed.
DFG Programme
Research Units
