GREENHOUSE GAS AND AMMONIA EMISSION MITIGATION PRIORITIES FOR UK POLICY TARGETS

Highlights

● An expert survey highlighted the most effective strategies for GHG and ammonia mitigation.

● Interventions considered to have the highest mitigation potential are discussed.

● Experts agreed that no single mitigation measure can uniquely deliver GHG and ammonia mitigation.

● Experts noted a need for further investment in research, knowledge exchange, education and to develop implementation pathways.

● There is a need for more data to better quantify mitigation potentials and implement effective management strategies.

Abstract

Agriculture is essential for providing food and maintaining food security while concurrently delivering multiple other ecosystem services. However, agricultural systems are generally a net source of greenhouse gases and ammonia. They, therefore, need to substantively contribute to climate change mitigation and net zero ambitions. It is widely acknowledged that there is a need to further reduce and mitigate emissions across sectors, including agriculture to address the climate emergency and emissions gap. This discussion paper outlines a collation of opinions from a range of experts within agricultural research and advisory roles following a greenhouse gas and ammonia emission mitigation workshop held in the UK in March 2022. The meeting identified the top mitigation priorities within the UK’s agricultural sector to achieve reductions in greenhouse gases and ammonia that are compatible with policy targets. In addition, experts provided an overview of what they believe are the key knowledge gaps, future opportunities and co-benefits to mitigation practices as well as indicating the potential barriers to uptake for mitigation scenarios discussed.

Graphical abstract

Keywords

agriculture / ammonia / greenhouse gas / mitigation / net zero

References

[1] National Statistics. 2020 UK Greenhouse Gas Emissions, Final Figures. National Statistics, 2022

[2] United Kingdom Government. Climate Change Act 2008 (2050 Target Amendment) Order 2019. Committee on Climate Change, 2022

[3] The Committee on Climate Change. Land Use: Policies for a Net Zero UK. Committee on Climate Change, 2020

[4] Eory V, MacLeod M, Topp C F E, Rees R M, Webb J, McVittie A, Wall E, Borthwick F, Watson C A, Waterhouse A, Wiltshire J, Bell H, Moran D, Dewhurst R J. Review and update the UK Agriculture Marginal Abatement Cost Curve to assess the greenhouse gas abatement potential for the 5th carbon budget period and to 2050: final report submitted for the project contract “Provision of services to review and update the UK agriculture MACC and to assess abatement potential for the 5th carbon budget period and to 2050”. Prepared for the Climate Change Committee, 2015

[5] United Kingdom Government. Mapping Carbon Emissions & Removals for the Land Use, Land-Use Change & Forestry Sector. Department of Energy & Climate Change (DECC) of UK, 2010

[6] Stark C, Thompson M, Andrew T, Beasley G, Bellamy O, Budden P, Cole C, Darke J, Davies E, Feliciano D, Gault A, Goater A, Hay R, Hemsley M, Hill J, Joffe D, Kmietowicz E, de Farias Letti B, Livermore S, Mackenzie C, Millar R, Nemo C, Scott V, Scudo A, Thillainathan I, Vause E. Net Zero: The UK’s Contribution to Stopping Global Warming. UK Committee on Climate Change, 2019

[7] Climate Change Committee. Progress in Reducing Emissions: 2022 Report to UK Parliament. Climate Change Committee, 2022

[8] Misselbrook T H, Gilhespy S L. Inventory of Ammonia Emissions from UK Agriculture 2020. Department for Environment, Food & Rural Affairs (DEFRA), 2022

[9] National Atmospheric Emissions Inventory (NAEI). Pollutant Information: Ammonia. Available at NAEI website on Augest 20, 2022,

[10] Department for Environment. Food and Rural Affairs (DEFRA). Code of Good Agricultural Practice (COGAP) for Reducing Ammonia Emissions. DEFRA, 2018

[11] Bracken C J, Lanigan G J, Richards K G, Müller C, Tracy S R, Grant J, Krol D J, Sheridan H, Lynch M B, Grace C, Fritch R, Murphy P N C . Sward composition and soil moisture conditions affect nitrous oxide emissions and soil nitrogen dynamics following urea-nitrogen application. Science of the Total Environment, 2020, 722: 137780

[12] Cummins S, Finn J A, Richards K G, Lanigan G J, Grange G, Brophy C, Cardenas L M, Misselbrook T H, Reynolds C K, Krol D J . Beneficial effects of multi-species mixtures on N₂O emissions from intensively managed grassland swards. Science of the Total Environment, 2021, 792: 148163

[13] Burchill W, Li D, Lanigan G J, Williams M, Humphreys J . Interannual variation in nitrous oxide emissions from perennial ryegrass/white clover grassland used for dairy production. Global Change Biology, 2014, 20(10): 3137–3146

[14] Phelan P, Casey I A, Humphreys J . The effect of target postgrazing height on sward clover content, herbage yield, and dairy production from grass-white clover pasture. Journal of Dairy Science, 2013, 96(3): 1598–1611

[15] McAuliffe G A, Takahashi T, Orr R J, Harris P, Lee M R F . Distributions of emissions intensity for individual beef cattle reared on pasture-based production systems. Journal of Cleaner Production, 2018, 171: 1672–1680

[16] International Panel on Climate Change (IPCC). 2006 IPCC Guidelines for National Greenhouse Gas Inventories. IPCC, 2006

[17] Abalos D, Rittl T F, Recous S, Thiébeau P, Topp C F E, van Groenigen K J, Butterbach-Bahl K, Thorman R E, Smith K E, Ahuja I, Olesen J E, Bleken M A, Rees R M, Hansen S . Predicting field N₂O emissions from crop residues based on their biochemical composition: a meta-analytical approach. Science of the Total Environment, 2022, 812: 152532

[18] International Fertiliser Association (IFA). Reducing Emissions from Fertilizer Use Report. IFA, 2022

[19] Eugène M, Klumpp K, Sauvant D . Methane mitigating options with forages fed to ruminants. Grass and Forage Science, 2021, 76(2): 196–204

[20] Cooledge E C, Chadwick D R, Smith L M, Leake J R, Jones D L . Agronomic and environmental benefits of reintroducing herb- and legume-rich multispecies leys into arable rotations: a review. Frontiers of Agricultural Science and Engineering, 2022, 9(2): 245–271

[21] Mkhonza N P, Buthelezi-Dube N N, Muchaonyerwa P . Effects of lime application on nitrogen and phosphorus availability in humic soils. Scientific Reports, 2020, 10(1): 8634

[22] Žurovec O, Wall D P, Brennan F P, Krol D J, Forrestal P J, Richards K G . Increasing soil pH reduces fertiliser derived N₂O emissions in intensively managed temperate grassland. Agriculture, Ecosystems & Environment, 2021, 311: 107319

[23] Gebremichael A W, Wall D P, O’Neill R M, Krol D J, Brennan F, Lanigan G, Richards K G . Effect of contrasting phosphorus levels on nitrous oxide and carbon dioxide emissions from temperate grassland soils. Scientific Reports, 2022, 12(1): 2602

[24] Tang X, Zhang C, Yu Y, Shen J, van der Werf W, Zhang F. Intercropping legumes and cereals increases phosphorus use efficiency; a meta-analysis. Plant and Soil, 2021, 460(1−2): 89−104

[25] Baggaley N J, Britton A J, Sandison F, Lilly A, Stutter M, Rees R M, Reed M, Buckingham S. Understanding Carbon Sequestration from Nature-based Solutions. ClimateXChange Publications, 2022

[26] Abdalla M, Hastings A, Cheng K, Yue Q, Chadwick D, Espenberg M, Truu J, Rees R M, Smith P . A critical review of the impacts of cover crops on nitrogen leaching, net greenhouse gas balance and crop productivity. Global Change Biology, 2019, 25(8): 2530–2543

[27] Newton I . The recent declines of farmland bird populations in Britain: an appraisal of causal factors and conservation actions. Ibis, 2004, 146(4): 579–600

[28] Lüscher A, Mueller-Harvey I, Soussana J F, Rees R M, Peyraud J L . Potential of legume-based grassland-livestock systems in Europe: a review. Grass and Forage Science, 2014, 69(2): 206–228

[29] Norton J, Ouyang Y . Controls and adaptive management of nitrification in agricultural soils. Frontiers in Microbiology, 2019, 10: 1931

[30] Klimczyk M, Siczek A, Schimmelpfennig L . Improving the efficiency of urea-based fertilization leading to reduction in ammonia emission. Science of the Total Environment, 2021, 771: 145483

[31] Zhang C, Song X, Zhang Y, Wang D, Rees R M, Ju X . Using nitrification inhibitors and deep placement to tackle the trade-offs between NH₃ and N₂O emissions in global croplands. Global Change Biology, 2022, 28(14): 4409–4422

[32] Cowan N, Carnell E, Skiba U, Dragosits U, Drewer J, Levy P . Nitrous oxide emission factors of mineral fertilisers in the UK and Ireland: a Bayesian analysis of 20 years of experimental data. Environment International, 2020, 135: 105366

[33] McGeough K L, Watson C J, Müller C, Laughlin R J, Chadwick D R . Evidence that the efficacy of the nitrification inhibitor dicyandiamide (DCD) is affected by soil properties in UK soils. Soil Biology & Biochemistry, 2016, 94: 222–232

[34] United States Department for Agriculture (USDA). New Zealand Dairy Industry Responds to Product Contaminant Issue. USDA, 2013

[35] Ray A, Nkwonta C, Forrestal P, Danaher M, Richards K, O’Callaghan T, Hogan S, Cummins E . Current knowledge on urease and nitrification inhibitors technology and their safety. Reviews on Environmental Health, 2021, 36(4): 477–491

[36] Duff A M, Forrestal P, Ikoyi I, Brennan F . Assessing the long-term impact of urease and nitrification inhibitor use on microbial community composition, diversity and function in grassland soil. Soil Biology & Biochemistry, 2022, 170: 108709

[37] Guo Y J, Di H J, Cameron K C, Li B, Podolyan A, Moir J L, Monaghan R M, Smith L C, O’Callaghan M, Bowatte S, Waugh D, He J Z . Effect of 7-year application of a nitrification inhibitor, dicyandiamide (DCD), on soil microbial biomass, protease and deaminase activities, and the abundance of bacteria and archaea in pasture soils. Journal of Soils and Sediments, 2013, 13(4): 753–759

[38] Matczuk D, Siczek A . Effectiveness of the use of urease inhibitors in agriculture: a review. International Agrophysics, 2021, 35(2): 197–208

[39] de Klein C A, Bowatte S, Simon P L, Arango J, Cardenas L M, Chadwick D R, Pijlman J, Rees R M, Richards K G, Subbarao G V, Whitehead D . Accelerating the development of biological nitrification inhibition as a viable nitrous oxide mitigation strategy in grazed livestock systems. Biology and Fertility of Soils, 2022, 58(3): 235–240

[40] Dimkpa C O, Fugice J, Singh U, Lewis T D . Development of fertilizers for enhanced nitrogen use efficiency—Trends and perspectives. Science of the Total Environment, 2020, 731: 139113

[41] Wiltshire J, Attree M, Carslaw D, Jenkins B, Martineau H, Virdo J. Ammonia futures: understanding implications for habitats and requirements for uptake of mitigation measures. Ricardo Energy & Environment, 2019

[42] Young M D, Ros G H, de Vries W . Impacts of agronomic measures on crop, soil, and environmental indicators: a review and synthesis of meta-analysis. Agriculture, Ecosystems & Environment, 2021, 319: 107551

[43] Abalos D, Jeffery S, Sanz-Cobena A, Guardia G, Vallejo A . Meta-analysis of the effect of urease and nitrification inhibitors on crop productivity and nitrogen use efficiency. Agriculture, Ecosystems & Environment, 2014, 189: 136–144

[44] Chadwick D, Sommer S, Thorman R, Fangueiro D, Cardenas L, Amon B, Misselbrook T. Manure management: implications for greenhouse gas emissions. Animal Feed Science and Technology, 2011, 166−167: 514−531

[45] Rabii A, Aldin S, Dahman Y, Elbeshbishy E . A review on anaerobic co-digestion with a focus on the microbial populations and the effect of multi-stage digester configuration. Energies, 2019, 12(6): 1106

[46] Riva C, Orzi V, Carozzi M, Acutis M, Boccasile G, Lonati S, Tambone F, D’Imporzano G, Adani F . Short-term experiments in using digestate products as substitutes for mineral (N) fertilizer: agronomic performance, odours, and ammonia emission impacts. Science of the Total Environment, 2016, 547: 206–214

[47] Lee M R F, Domingues J P, McAuliffe G A, Tichit M, Accatino F, Takahashi T . Nutrient provision capacity of alternative livestock farming systems per area of arable farmland required. Scientific Reports, 2021, 11(1): 14975

[48] Meier J, Andor M A, Doebbe F C, Haddaway N R, Reisch L A . Review: do green defaults reduce meat consumption?. Food Policy, 2022, 110: 102298

[49] Funke F, Mattauch L, van den Bijgaart I, Godfray H C J, Hepburn C, Klenert D, Springmann M, Treich N . Toward optimal meat pricing: is it time to tax meat consumption. Review of Environmental Economics and Policy, 2022, 16(2): 219–240

[50] Willett W, Rockström J, Loken B, Springmann M, Lang T, Vermeulen S, Garnett T, Tilman D, DeClerck F, Wood A, Jonell M, Clark M, Gordon L J, Fanzo J, Hawkes C, Zurayk R, Rivera J A, De Vries W, Majele Sibanda L, Afshin A, Chaudhary A, Herrero M, Agustina R, Branca F, Lartey A, Fan S, Crona B, Fox E, Bignet V, Troell M, Lindahl T, Singh S, Cornell S E, Srinath Reddy K, Narain S, Nishtar S, Murray C J L . Food in the Anthropocene: the EAT-Lancet commission on healthy diets from sustainable food systems. Lancet, 2019, 393(10170): 447–492

[51] Westhoek H, Lesschen J P, Rood T, Wagner S, De Marco A, Murphy-Bokern D, Leip A, van Grinsven H, Sutton M A, Oenema O . Food choices, health and environment: effects of cutting Europe’s meat and dairy intake. Global Environmental Change, 2014, 26: 196–205

[52] Leip A, Billen G, Garnier J, Grizzetti B, Lassaletta L, Reis S, Simpson D, Sutton M A, de Vries W, Weiss F, Westhoek H . Impacts of European livestock production: nitrogen, sulphur, phosphorus and greenhouse gas emissions, land-use, water eutrophication and biodiversity. Environmental Research Letters, 2015, 10(11): 115004

Acknowledgements

Many thanks to the Association of Applied Biologist’s for organizing and hosting the “Agricultural greenhouse gases and ammonia mitigation: solutions, challenges, and opportunities” workshop. This work was supported with funding from the Scottish Government Strategic Research Programme (2022−2027, C2-1 SRUC) and Biotechnology and Biological Sciences Research Council (BBSRC) (BBS/E/C/000I0320 and BBS/E/C/000I0330). We also acknowledge support from UKRI-BBSRC (UK Research and Innovation-Biotechnology and Biological Sciences Research Council) via grants BBS/E/C/000I0320 and BBS/E/C/000I0330, and Rothamsted Research Science Initiative Catalyst Award supported by BBSRC.

Compliance with ethics guidelines

Sarah Buckingham, Cairistiona F. E. Topp, Pete Smith, Vera Eory, David R. Chadwick, Christina K. Baxter, Joanna M. Cloy, Shaun Connolly, Emily C. Cooledge, Nicholas J. Cowan, Julia Drewer, Colm Duffy, Naomi J. Fox, Asma Jebari, Becky Jenkins, Dominika J. Krol, Karina A. Marsden, Graham A. Mcauliffe, Steven J. Morrison, Vincent O'Flaherty, Rachael Ramsey, Karl G. Richards, Rainer Roehe, Jo Smith, Kate Smith, Taro Takahashi, Rachel E. Thorman, John Williams, Jeremy Wiltshire, and Robert M. Rees declare that they have no conflicts of interest or financial conflicts to disclose. This article does not contain any studies with human or animal subjects performed by any of the authors.

RIGHTS & PERMISSIONS

The Author(s) 2023. Published by Higher Education Press. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0)