Soil-atmosphere fluxes of CO2 and CH4 in annual and perennial cropping systems in southern Sweden

Annual cropping systems dominate agricultural grain production, but have been linked to several key environmental issues, such as loss of biodiversity and pollution of groundwater. Newly developed perennial grains may offer solutions to some of those problems. Their longer roots and growing seasons theoretically enable them to act as sinks of atmospheric carbon. This study set out to compare soil-atmosphere fluxes of CO2 and CH4 from annual and perennial cropping systems at a study site in southern Sweden. The site comprised two adjacent fields, one growing the perennial grain intermediate wheatgrass, the other following an annual crop rotation. Using the chamber method, soil-atmosphere fluxes of CO2 and CH4 were measured at five plots in each field. Measurements commenced in the perennial field in July 2024, and comparable measurements from both fields were taken biweekly from October 2024 to May 2025. Concurrent measurements of soil temperature and soil water content were also taken. CO2 fluxes exhibited large temporal variability, but low spatial variability, while CH4 fluxes exhibited large spatiotemporal variability. CO2 fluxes were found to have a positive exponential relationship with soil temperature, whereas CH4 fluxes were found to have a negative linear relationship with soil water content. No significant differences in mean CO2 fluxes were found between the two fields, but the perennial field showed a significantly larger mean soil uptake of CH4 than the annual field. Mean temperature sensitivity was greater in the perennial field, but both fields were found to have high temperature sensitivity at low soil temperatures. These results suggest promising climate benefits from perennial grains, but underscore the need for long-term, full-season studies to better understand how annual and perennial cropping systems influence soil–atmosphere fluxes of greenhouse gases.

Author dc:creator

• Rasmus Raasthøj Falck 1996-

Contributors dc:contributor

• Landbúnaðarháskóli Íslands

• Umhverfisbreytingar á norðurslóðum
• EnCHiL

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/1946/51379

OAI identifier oai:identifier

oai:skemman.is:1946/51379