EGU22-4585
https://doi.org/10.5194/egusphere-egu22-4585
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Nitrous oxide emission peaks and distribution of nitrous oxide in the soil profile during rain events: A soil column experiment

Line Vinther Hansen1, Andreas Brændholt1, Azeem Tariq1,2, Lars Stoumann Jensen1, and Sander Bruun1
Line Vinther Hansen et al.
  • 1Department of Soil and Environmental Sciences, University of Copenhagen, Denmark (livh@plen.ku.dk)
  • 2School of Environmental Sciences, University of Guelph, Canada (atariq02@uoguelph.ca)

Nitrous oxide (N2O) emissions are notoriously variable at different spatial and temporal scales. As recognized in the literature, peaks in emissions of N2O occur after fertilization, precipitation and freeze-thaw events. Although the individual microbial processes have been extensively studied, the understanding of the underlying mechanisms behind the pulse emissions is still subject to many uncertainties. The N2O produced in connection with a rain event can either be entrapped in the soil matrix and be subject to N2O reduction or be released later when soil diffusivity increases as water infiltrate into the soil or evaporate.

To understand the mechanisms behind the observed flux emissions related to precipitation events, we are conducting a laboratory experiment to quantify the N2O movement in the soil. In 50 cm tall soil columns exposed to a simulated rain event, gas samples are extracted from the soil matrix at three depths via reinforced silicone tubes. At the surface, gas is sampled for flux estimates.

A common trigger of pulse emissions is a lowered soil oxygen content. Continuous monitoring of the soil oxygen with sensors at three depths provides measurements of O2 dynamics in the soil simultaneously with the N2O content. This can add to the understanding of how O2 relates to N2O production, reduction and movement. Tensiometers will additionally provide data on the soil water status during simulated precipitation events.

The experimental set-up can furthermore be used for studying the effects of other factors affecting N2O movement and emission in soil e.g., soil types, type of fertilizers, soil temperature etc. 

 

 

How to cite: Hansen, L. V., Brændholt, A., Tariq, A., Jensen, L. S., and Bruun, S.: Nitrous oxide emission peaks and distribution of nitrous oxide in the soil profile during rain events: A soil column experiment, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4585, https://doi.org/10.5194/egusphere-egu22-4585, 2022.

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