Greenhouse gas emissions, carbon sequestration and biodiversity: the potential impact of Agri-environment schemes on arable land Seminar

Abstract: 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 provides financial incentives for land managers to implement 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 calculated 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 were highlighted and prioritised.

Emissions reduction occurred 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, risking production displacement of system leakage.  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.  A habitat suitability index approach identifies additional benefits for biodiversity where appropriately spatially targeted.

References

Mondière, A., Tzilivakis, J., Warner, D. J., van der Werf, H. M. G., Farruggia, A., Glinec, O., & Corson, M. S. (2023). An improved indicator framework to assess and optimise ecosystem services provided by permanent grasslands. Ecological Indicators, 146, 109765.

Tzilivakis, J., Warner, D., & Holland, J. (2019). Developing practical techniques for quantitative assessment of ecosystem services on farmland. Ecological Indicators, 106, [105514].

Warner, D., Tzilivakis, J., Green, A. & Lewis, K. (2020). Establishing a field-based evidence base for the impact of agri-environment options on soil carbon and climate change mitigation – phase 1. Final Report. Work package number: ECM50416, Evidence Programme Reference number: RP04176, Natural England.

Warner, D., Tzilivakis, J., Green, A. & Lewis, K. (2017). Prioritising agri-environment options for greenhouse gas mitigation. International Journal of Climate Change Strategies and Management, vol. 9, no. 1, pp. 104-122.

Speaker Information

Douglas Warner

Douglas Warner - Research Database - University of Hertfordshire (herts.ac.uk)

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