[This dataset is embargoed until January 2, 2026]. This dataset contains information on the soil particle size distribution and the 12 & 13 CO2 fluxes from varying permafrost soil types and horizons sampled from the North West Territories and Yukon, Canada in 2019 and 2020. The soils were used in a continuous labelling experiment with live Agrostis capillaris growing into them with corresponding root-free controls. The recorded flux data is used to derive the rhizosphere priming effect in the tested soils. Full details about this dataset can be found at https://doi.org/10.5285/a80c688c-0a91-41ce-a8e9-89479a38a566