Measuring N2 and N2O fluxes and related processes at high sensitivity and resolution in the field using advanced isotopic tools as a basis for model evaluation – Subproject P6 of the research unit "Denitrification in Agricultural Soils: Integrated Control and Modelling at Various Scales” (DFG RU 2337)
To better predict gaseous nitrogen emissions from agricultural soils via microbial processes, robust data on N2 emissions and oxygen depletion in soil are needed. Our task is to conduct field and laboratory studies in order to address this knowledge gap.
Denitrification is the anaerobic microbial process through which nitrate (NO3-) and nitrite (NO2-) are reduced to molecular nitrogen (N2) via the following reaction steps: NO3- → NO2- → NO → N2O → N2. A significant fraction of the nitrous oxide (N2O) produced within this process is not further reduced to N2 and instead constitutes the main emission source of this greenhouse gas from agricultural soils. Hence, our understanding and ability to quantify soil denitrification is crucial for reducing N2O emissions and nitrogen fertiliser loss.
Robust denitrification data suitable to validate N2 fluxes in denitrification models are scarce due to the methodological complexities in collecting such data and the extreme spatio-temporal heterogeneity of denitrification. The coordinated DFG research unit „Denitrification in Agricultural Soils: Integrated Control and Modelling at Various Scales (DASIM)” (http://www.dasim.de) investigates the denitrification process chain in agricultural soils using advanced analytical and molecular biological methods as well as field studies and various modelling approaches. The aim is to investigate the activity and regulation of denitrification in unprecedented spatial and temporal resolution and to use the results to develop mathematical models from the micro-scale to the field scale, in order to improve existing simulation approaches.
DASIM is a joint project, which is divided into eight different parts. At the Thuenen Institute of Climate-Smart Agriculture, we will address the questions in Subproject P6. Our tasks are to:
The questions to be addressed across the entire DASIM research unit are:
The questions addressed in our subproject (P6) are:
1.2020 - 12.2022
Project status: ongoing