Can peatlands be used sustainably for agriculture in the Arctic Norway?

Large areas of peatlands have been drained for agricultural and forestry purposes due to human activities. This drainage disrupts the natural hydrology of peatlands, leading to increased peat decomposition and turning these ecosystems into significant sources of greenhouse gas (GHG) emissions. Since the 1930s, extensive peatland areas in northern Norway have been drained and converted to agricultural land. To mitigate GHG emissions while maintaining biomass production, various management practices, including rewetting, are being promoted for these peatlands. Nevertheless, the impact of these mitigation measures on the peatland GHG balance remains largely unexplored.

We investigated grass productivity and the GHG balance in response to peatland cultivation under varying fertilization and hydrological treatments at a site in northern Norway. GHG fluxes (CO₂, CH₄, and N₂O) were measured using 30 automatic chambers at sub-daily intervals during the growing seasons of 2022-2024.

High water levels inhibited CO₂ emissions by suppressing ecosystem respiration, converting the ecosystem from a substantial CO₂ source to a sink or neutral state. Conversely, high water levels enhanced CH₄ emissions, while low water level plots remained CH₄ neutral. Sporadic N₂O emissions were observed to be higher under the more intensive fertilization regimen. Our results further highlight the critical role of harvest in determining the overall GHG and carbon balance in the ecosystem. This study has significant implications for guiding sustainable peatland management in Arctic regions.