Greenhouse gas mitigation in agriculture has been so far relying mostly on voluntary implementation; policy, in their attempt to step up effort in agriculture, requires more reliable information on mitigation practices, including their current and potential future uptake. Expert elicitation techniques can estimates where otherwise the data gaps exist. A four stage Deplhi expert elicitation was carried out to estimate the uptake and its uncertainty for five mitigation practices under three policy scenarios in Scotland. The current uptake was estimated to be 5-68%, the uptake in 10 years͛ time with no policy change was between 10-70% and the future uptake with targeted policy was 50-83%. The uncertainty (difference between lower and upper quartile estimates) was between 6-40%. The highest policy effect was estimated to be expected from targeting nitrification inhibitor uptake. Policy supporting improved land drainage and regulatory approaches for nitrogen management practices could achieve only lower policy effect (13-22%) but with a higher confidence. The elicitation also highlighted that clear definitions of farming practices are very important and expert estimates would ideally involve stakeholders from different backgrounds.