Soil Carbon Emissions Raise Milk’s Climate Impact by 41%, Study Shows

Context Traditional dairy carbon footprints focus mainly on methane from cows, overlooking changes in soil organic matter. The study used life‑cycle assessment with eddy‑covariance towers and the DNDC model to measure seasonal soil carbon stocks across grass‑cereal rotations. This approach captures both carbon sequestration by grass roots and emissions from soil disturbance.

Key Facts Factoring in soil carbon raises milk production’s total emissions by 41 percent relative to calculations that exclude it. Grassland root systems continuously add carbon to the soil, making these fluxes essential for accurate dairy footprint assessments. When dairy farms convert grassland to cereal crops, the soil can release up to five times more carbon than when the land remains as grassland.

What It Means The findings suggest that current reporting standards understate dairy’s climate impact by neglecting soil dynamics. Farmers and policymakers may need to revise land‑use practices, such as preserving grasslands or adopting rotations that limit soil carbon loss. Future research should monitor how freeze‑thaw cycles and droughts alter soil carbon balances in northern dairy regions.

Watch for updates to national greenhouse‑gas inventories that begin incorporating soil carbon fluxes from agricultural lands.