Peatlands drained for agriculture are among the most intensive sources of greenhouse gas (GHG) emissions from the land-use sector. Policy decisions on the most effective strategies to reduce GHG emissions in line with Paris Agreement goals, alongside strategies that can halt any ongoing soil and biodiversity losses, are hindered by a lack of understanding on how proposed mitigation measures are likely to be received by the farming sector. Research has identified effective GHG reduction measures, but successful on-farm adoption of these measures is contingent upon farmer perceptions of the relative practicality of implementing the measures, and the economic impact that adoption will have on the farm business. In this study, Best–Worst Scaling, a discrete choice survey method, was utilised to elicit expert (climate change, policy and biodiversity) and farmer opinion on the relative effectiveness, practicality and level of economic cost of mitigation measures that can reduce GHG emissions at the farm level. The method enabled individual mitigation measures to be ranked by effectiveness (expert opinion), practicality and economic cost (farmer opinions). There were no measures ranked as both effective and practical, or effective with low cost, but there were measures ranked by farmers as practical and low cost to implement. These included: more effective nutrient management, reduced or no tillage, the installation of buffer zones, increased fossil fuel efficiency and the optimisation of irrigation systems. The strong divergence of ‘effective’ measures on the one hand, and ‘practical’ and ‘economic’ measures on the other, highlights the major challenges involved in reducing high GHG emissions from agricultural organic soils. Resolving these challenges will require a combination of financial mechanisms to compensate farmers for higher costs and/or reduced yields, engagement and advice to support farmers in adopting changes in management practice, and agricultural innovation and adaptation to maintain overall food production and economic viability. If these challenges are overcome, more sustainable landscape management on agricultural lowland peat could make significant contributions to achieve national and international climate change targets.