Soil nitrogen transformations – advances in quantification and process-based modelling

Co-organized by SSS5

Convener: Balázs Grosz | Co-conveners: Jaqueline Stenfert Kroese, Johannes Friedl, Clemens Scheer, Reinhard Well

The study of nitrogen (N) processes in soils has a long and distinguished history. Recent research efforts have targeted the direct quantification of N turnover in the soil plant atmosphere system across scales. Nevertheless, methodological constraints, the high spatial and temporal variability of soil N transformation, and the multitude of interacting factors determining N availability and loss from soils presents significant challenges that make accurate quantification difficult, thereby limiting our quantitative understanding of the N turnover.
Although the factors controlling N turnover in soils are relatively well established under laboratory conditions, transposing these relationships to the field and landscape scales remains a significant challenge. The absence of data-sets collected in-situ impedes the validation of N processes, such as mineralization and denitrification simulated via process-based models, thereby rendering their results at field and regional scales highly uncertain. However, current ecosystem management challenges require accurate predictions of N fate to enable sustainable management that minimizes environmental losses.

We invite contributions from the following fields:
• Methodological advances in measuring and modelling of soil N processes, spanning from the micro- to the landscape scale;
• Measurements of N fluxes including specific loss pathways under field or field-like conditions with a focus on identifying controlling factors;
• Comparative studies demonstrating/evaluating novel approaches to constrain N turnover such as incubation under He/O2 atmosphere, 15N-tracer technique, N2O isotopologue approaches or other innovative methods;
• Process-based modelling of soil N processes at various scales;
• Linking nitrogen transformation rates to the function and structure of the soil microbial community.