Stephanie Gerin, Henriikka Vekuri, Maarit Liimatainen, Juha-Pekka Tuovinen, Jarkko Kekkonen, Liisa Kulmala, Tuomas Laurila, Maiju Linkosalmi, Jari Liski, Erkki Joki-Tokola, Annalea Lohila, Two contrasting years of continuous N2O and CO2 fluxes on a shallow-peated drained agricultural boreal peatland, Agricultural and Forest Meteorology, Volume 341, 2023, 109630, ISSN 0168-1923, https://doi.org/10.1016/j.agrformet.2023.109630
Two contrasting years of continuous N₂O and CO₂ fluxes on a shallow-peated drained agricultural boreal peatland
|Author:||Gerin, Stephanie1; Vekuri, Henriikka1; Liimatainen, Maarit2,3;|
1Finnish Meteorological Institute, Climate System Research Unit, P.O. Box 503, 00101 Helsinki, Finland
2Natural Resources Institute, University of Oulu, Paavo Havaksen tie 3, FI-90014, Finland
3Water, Energy and Environmental Engineering Research Unit, University of Oulu, P.O. Box 8000, FI-90014, Finland
4Institute for Atmospheric and Earth System Research, Forest Sciences, University of Helsinki, P.O. Box 27, 00014, Finland
5Institute for Atmospheric and Earth System Research, Physics, University of Helsinki, P.O. Box 64, 00014, Finland
|Online Access:||PDF Full Text (PDF, 2.9 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe20231030141925
|Publish Date:|| 2023-10-30
Drained agricultural boreal peatlands comprise a large source of nitrous oxide (N₂O) and carbon dioxide (CO₂) but a small sink or source of methane (CH₄). N₂O fluxes have high spatial and temporal variability and are often measured with the chamber technique. Therefore, continuous measurements of N₂O fluxes are needed to better understand how N₂O emissions are triggered and to reduce the uncertainty of annual N₂O budget estimations. Here we present a two-year-long time series of continuous measurements of CO₂ and N₂O fluxes of a shallow-peated drained agricultural boreal peatland cultivated for grass silage. The fluxes were measured with the area-averaging eddy covariance technique. Several NO peak events were observed throughout all seasons. The peaks were associated with meteorological or management events, such as soil thawing or freezing, precipitation, fertilization and glyphosate application. The annual N₂O budget was 4.74 ±0.47 and 6.08 ±0.49 kg NO-N ha⁻¹ y⁻¹ in 2020 and 2021, respectively. The annual CO₂ budget, comprising the sum of net ecosystem exchange and biomass export, was 3.70 ±0.22 and 5.54 ±0.33 t CO₂-C ha⁻¹ y⁻¹ in 2020 and 2021, respectively. The N₂O budget during the first, warmer winter was 106% higher than during the second, meteorologically more typical winter, due to the higher frequency of soil freezing–thawing cycles. The average annual NO budget was 36%–50% lower than the IPCC Emission Factor (EF) while the CO₂ budget was in accordance with the IPCC EF. CO₂ emissions dominated the total CO₂-eq emissions of our site but N₂O also had a significant contribution of 12%. Our results also suggest that glyphosate application enhanced N₂O emissions in the last quarter of 2021. However, the full rotation should be measured to confirm whether there is a need to re-evaluate the N₂O IPCC EF for ‘grassland drained boreal’ land-use class.
Agricultural and forest meteorology
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1172 Environmental sciences
We also thank Maj and Tor Nessling Foundation, Finland (grant no. 202000391), Kone foundation, Finland (grant no. 201802192), Suoviljelysyhdistys, Finland (project Ojitettujen turvemaiden ympäristövaikutukset ja mahdollisuudet hillitä haitallisia vaikutuksia), Niemi Foundation, Finland (grant no. 20200074), Centre for Economic Development, Transport and the Environment, Finland (grant no. 190444), Rural development program, Finland (grant no. 83215), the Ministry of Agriculture and Forestry of Finland MMM (Eloperäisten maiden viljelyn ympäristökuormituksen vähentäminen and NC-GRASS), The Strategic Research Council at the Academy of Finland (decisions 327214 and 352431) and the Academy of Finland Flagship Program (decision no. 337552).
© 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).