Reducing agricultural greenhouse gas emissions and enhancing carbon sequestration through Agri-environment schemes on arable land

Greenhouse gas emissions from the arable food sector are dominated by supplementary nitrogen fertiliser application, nitrous oxide from soils, and to a lesser extent fossil fuels to power farm machinery. Countryside Stewardship is the current agri-environment scheme in England, providing financial incentives for land managers implementing management to benefit wildlife while protecting water resources and reducing flood risk. It also aims to mitigate climate change through changes in land use and management.
A life-cycle analysis approach has been used to calculate a greenhouse gas balance for Countryside Stewardship options on arable land, accounting for both an absolute (total) emissions reduction, and impact where crop yield is taken into consideration. All aspects of the crop production cycle were considered, agro-chemical application, direct emissions from fuel consumption, upstream emissions associated with product manufacture and emissions from soils. Options with the potential to mitigate greenhouse gas emissions and / or enhance carbon sequestration have been highlighted and prioritised.
Countryside Stewardship can reduce agricultural greenhouse gas emissions in two main ways: (1) a decrease in overall emissions, (2) an increase in the carbon sequestered in soil and biomass. Most options achieve an absolute reduction in greenhouse gas emissions relative to an arable crop but at the expense of removing land from production. Key options that reduce emissions without compromising yield include those that protect soils at risk to erosion (e.g. SW5 Enhanced management of maize crops) or reduce nitrate leaching (e.g. SW6 Winter cover crops). Strategically located within field grass areas may reduce nitrous oxide emissions from surface run-off in addition to the emissions reduction from the removal of crop management activities. Countryside Stewardship has the potential to reduce agricultural greenhouse gas emissions with appropriate farm specific spatial targeting.