FarmLCA: A novel approach to assess agroecological innovations in Life Cycle Assessment

Summary

Context
Agroecological innovations are seen as solutions to reduce environmental impacts of agriculture but can potentially lead to trade-offs with food production. Appropriate tools are needed to better understand synergies and trade-offs among environmental issues, resource efficiency and food production.
Objective
This study presents the FarmLCA tool, which models farms as interconnected crop-livestock systems and assesses environmental impacts from farms and farm-inputs. A mixed beef farm serves as case study to assess synergies and trade-offs of avoiding human edible feed in beef production.
Methods
FarmLCA allows the calculation of cradle-to-farm gate life cycle assessments (LCA). Emissions of environmentally harmful substances from crops and livestock are modelled based on the farm management. Upstream impacts from imported inputs (including fertilizer or feed) are accounted for with life cycle inventory data. Yields and nutrient requirements are checked for plausibility, based on management handbooks, while manure availability and composition are calculated based on livestock production. Environmental impacts, nutrient use efficiency and food production for a typical mixed beef farm in Scotland were calculated (baseline) and compared to alternative farm management scenarios: a Feed-no-Food scenario, avoiding concentrate feeds resulting in a smaller herd size and a circular Feed-no-Food scenario, additionally optimizing productivity and synergies between crop and livestock (e.g. more legumes in crop rotation, reduced replacement rate and feed waste).
Results and conclusions
In the Feed-no-Food scenario, the beef production was reduced by 25 %, but more calories and protein were produced overall due to cereal and legumes now being available for direct human consumption. However, slower growth of livestock led to increased environmental impact of beef, whilst reduced livestock numbers required more mineral fertilizer for crop production to replace on-farm manure. In the circular Feed-no-Food scenario, beef and overall calorie production were slightly reduced compared to the baseline, but 1.5 more high quality protein (expressed by the Digestible Indispensable Amino Acid Score, DIAAS), were produced. Environmental impacts of beef were reduced and nitrogen self-sufficiency improved due to increased legume share in the rotation.
Significance
Existing LCA approaches often fail to capture the complex dynamics of integrated crop-livestock systems and agroecological practices. FarmLCA addresses this by modelling both on-farm processes and upstream inputs, enabling a consistent assessment of environmental impacts, nutrient use efficiency, and food production. It offers a more holistic and systemic view of the consequences of agroecological innovations and enables the identification of synergies and trade-offs between environmental protection, resource efficiency, and food production.