Joe Lloyd, analyst in Savills rural research comments, “Agricultural machinery is expected to work hard, often in challenging terrain, using 100’s of litres of fuel a day and often requiring refuelling out in the field. Fuel typically accounts for 4 to 5 percent of an arable farmer’s cost of production and the practicalities of any replacement could impact productivity too.”

All the alternatives have drawbacks. Batteries are unable to simultaneously deliver the power and range required. Hydrogen fulfils a number of the requirements for farm fuel but the infrastructure remains underdeveloped and expensive. Biomethane is currently the choice for sustainably-fuelled machinery, having a number of the better traits associated with diesel, but would require large upfront expenditure on dedicated machinery and the accompanying infrastructure.

Biomethane is currently the most likely candidate for widescale adoption and some mainstream manufacturers already offer biomethane fuelled tractors. Biomethane offers a number of environmental benefits, such as a low carbon cost, the potential to capture methane emissions from slurry lagoons for processing into this fuel, and the promotion of a circular economy on-farm. Integrated within a bioenergy with carbon capture and storage system, biomethane fuel may form part of a carbon negative farming system in the future.

Such possibilities are a long way off however, and a number of practical issues must be tackled beforehand.

Duncan Winspear Savills food and farming consultant comments, “A viable alternative fuel to diesel is a key factor in reducing carbon emissions. There is a lot of innovation in this sector and, for example, bioethanol is already used for some machine work. However, there is a way to go before alternatives to diesel become mainstream with challenges to overcome including safe on farm storage, ease of transportation to off lying land or the refuelling of machinery working continuously in fields.

Despite this, environmental and economic factors mean diesel’s time as a farm fuel is limited and an alternative must be sought to ensure the long term viability of farming businesses and agriculture as a whole in the UK.