Food on Peat: The impact of wetter farming practices on greenhouse gas emissions from food crops on agricultural lowland peat bogs in the Northwest of England.

Up to 40% of U.K. grown vegetables are produced on lowland peat. This land use type is the highest emitter of carbon per unit area in the U.K., with drained agriculture on peatlands representing 3% of reported national greenhouse gas (GHG) emissions. This land use type impacts many other ecosystems service including the loss of topsoil and compaction, increased flood risk and biodiversity. However, total agricultural production from lowland peat equates to £1.23 billion in U.K. revenue providing income to farmers and jobs in the local area. Paludiculture and wetter farming are increasingly being considered as more sustainable alternatives to conventional farming to enable the continued productive use of peatlands whilst mitigating the impacts of peatland cultivation. Whilst there are several trials considering various paludiculture crops, there is a gap in the research which focuses on food crops in the U.K. We present the preliminary findings of a three-year wetter farming experiment focused on food crops in which carbon dioxide (CO₂) and methane (CH₄) emissions were measured from three agricultural lowland peat bog (ALPB) sites in the Northwest of England. The wetter farming experimental site in Greater Manchester was rewetted in March 2022. Celery (2022, 2023 and 2024) and lettuce (2024) crops were grown at a higher water table with annual averages of between 30.5 cm and 38.8 cm below the soil surface. The other two sites represented business as usual (BaU) drainage agriculture on ALPB with annual average water table depths between 69.1 cm and 96.2 cm below the soil surface. Both BaU sites are situated in Lancashire; one is a vegetable farm at which celery (2022, 2023 and 2024) and lettuce (2024) crops were monitored, the other farm is cereal farm where wheat fields were monitored (2022 and 2023). CO₂ and CH₄ emissions factors for the cultivation of these crops at various water table depths will be presented. In addition, we will discuss the impacts of specific farming activities (ploughing/cultivation, planting, fertilizer application and harvest) on CO₂ and CH₄ emission at all three sites. These emissions will be linked to both soil chemistry and physical attributes.