A recent study reveals multiple ways to lower emissions in pasture-based beef production.
The findings of the research conducted by the North Wyke Farm Platform at Rothamsted Research, in collaboration with Harper Adams University, were published in the International Journal of Life Cycle Assessment (LCA).
According to Michael RF Lee, deputy vice-chancellor at Harper Adams University, the research showed that emissions could be reduced by 7.5%, 12%, and 26% through the application of nitrification inhibitors, the introduction of white clover, and improved manure management using anaerobic digestion, respectively.
Lee shared the results in a social media post, emphasizing the practical implications of these strategies.
The study also explored the impact of reducing livestock density. While this measure decreased total emissions per unit of land, it paradoxically increased emissions per unit of product by 25%. These findings highlight the complexity of balancing environmental and productivity goals in livestock farming.
Another significant area of focus was the role of soil organic carbon (SOC) in emission mitigation. The researchers stressed the need for improved understanding of SOC dynamics under various management practices, as current models and assumptions often fail to reflect observed data.
Context and challenges
Globally, agri-food systems face increasing pressure to reduce greenhouse gas (GHG) emissions, particularly nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4). In the UK, agriculture contributes approximately 10% of total GHG emissions, with 56% of these emissions arising from livestock production, reported the team.
Ruminants, particularly beef cattle, are responsible for 70–80% of total livestock emissions, representing a significant target for mitigation efforts, they added.
Method
The study developed a ‘business-as-usual’ (BAU) partial cradle-to-finishing farmgate model based on primary data from the North Wyke Farm Platform. This BAU system incorporated the RothC process-based soil organic carbon model into a life cycle assessment (LCA) framework to evaluate trade-offs associated with various mitigation strategies.
The interventions assessed included:
- Extensification (reducing livestock density),
- Anaerobic digestion technology for manure management,
- Application of the nitrification inhibitor DCD, and
- Substitution of synthetic nitrogen fertilizers with nitrogen fixed by legumes like white clover.
Results
The results showed that the partial carbon footprint for 1kg of beef liveweight gain could be reduced by:
- 7.5% using nitrification inhibitors,
- 2% via the introduction of white clover (pending successful establishment),
- 26% with the adoption of anaerobic digestion technology.
Conclusions
The researchers said their study shows the importance of considering emissions across the entire lifecycle of agricultural systems to accurately assess their sustainability.
“The LCA approach enabled the assessment of interactions between different components of a highly instrumented beef production farm (in terms of feed production and quality, animal performance, manure management procedures, and material inputs and outputs, which are all measured/recorded meticulously and frequently) and its potential climate impacts under various scenarios.
“While beef production can contribute significantly to global warming, the different mitigation measures concerning manure management (anaerobic digestion) and grassland management (nitrification inhibitor, white clover introduction) were shown to be effective for reducing the global warming of the beef farming system.
“The findings in this paper emphasised the importance of reporting impacts of management scenarios on changes in SOC when applying LCA to assess the sustainability of agri-food production systems, despite their minimal effect in our specific case study.”
Source: The International Journal of Life Cycle Assessment
Title: Carbon footprints of greenhouse gas mitigation measures for a grass-based beef cattle finishing system in the UK
Authors: Jebari, A., Takahashi, T., Lee, M.R.F. et al
