Measuring and modelling greenhouse gas emissions and nitrate leaching of raw material crop rotations (MASTER)
Within the project MASTER we examine strategies to reduce nitrous oxide emissions and carbon dioxide emissions from raw material crop rotations. We analyse long term field experiments and use biogeochemical process models to estimate mitigation efficiencies.
There is an increasing need for sustainable biomass production at the national and global scale. Bioenergy production contributes to climate protection because fossil energy sources can be substituted. Energy efficiency and GHG mitigation by agricultural biomass production are highly variable depending on the established management system and site specific environmental conditions. Meaningful GHG balances of these systems have to consider all GHG fluxes including direct and indirect N2O emissions from managed soils and CO2 fluxes by changing soil humus stocks.
The project “Measuring and quantifying mass flows in agro-ecosystems for greenhouse gas mitigation (MASTER)” analyses GHG budgets of various crop rotations for biomass production. Within MASTER our sub project “Measuring and modelling of greenhouse gas emissions and nitrate leaching in bioenergy crop rotations” aims to enable the process based model DNDC to estimate nitrous oxide emissions, nitrate leaching, crop growth of raw material crops and soil carbon stock development. We are interested in the relationship between greenhouse gas fluxes from managed soils shortly after establishing crop rotations for biomass use and after several decades when equilibrium between carbon inputs and outputs is reached.
Mitigation measures for raw material crop production will be assessed based on model results of the parameterized DNDC for important soil-climate mapping units across Germany.
The project is based on three longterm field experiments with raw material production in Viehhausen, Roggenstein (Bavaria) and Trossin (Saxonia). Each experiment covers several raw material crop rotations and treatments with variable N fertilisation types and rates.
During the project duration, measurements of nitrous oxide emissions for specific crops will be conducted by project partners TU München and LfULG. The Thünen Institute will analyse gas samples taken at the experimental plots. Because the experiment duration already covers about 6 to 13 years changes in soil organic carbon stocks in dependence on crop rotation and organic amendments can be quantified.
The experimental data will be used to calibrate the process based model DNDC addressing biomass production, nitrous oxide emissions and Corg changes in the topsoil horizon. We will conduct multi-site calibrations, e.g. searching for “global” parameter fields with best model performance for the combined field experiments. Model validation will be performed using data from completed projects (“Joint project: development and comparison of optimized production systems for the agricultural production of energy crops under the different conditions at different locations in Germany (EVA)”).
The calibrated model will be used to estimate effects of locally adapted mitigation options for climate-soil mapping units across Germany. Simulation periods will cover several decades to quantify effects after crop rotation establishment and at equilibrium. Mitigation scenarios will also cover a range of intensities of mitigation options (for instance a variable ratio of N from digestate application and mineral fertilisation or the frequency of intercrops.)
3.2019 - 2.2022
Project funding number: 22032018
Funding program: FNR
Project status: ongoing