Abstract

PurposeThe purpose of using circularity indicators is to show the effect of changes from linear to more circular systems. This paper contributes to highlighting the importance of methodological aspects of circularity indicators in the agricultural sector when using a life cycle thinking approach. Selected circularity indicators have been explored and compared with LCA impact categories by using them to evaluate the circularity of a livestock system.MethodsCircularity indicators were tested on a theoretical pig production system where several circularity strategies and associated mitigation actions were applied. The strategies and mitigation actions were as follows: anaerobic digestion of manure (closing resource loops), anaerobic digestion of bread waste (closing resource loops), precision fertilization (narrowing resource loops), use of cover crops in feed production (regenerating resource flows), and use of bread waste as feed (slowing resource loops). The functional unit was 1 kg pork as carcass weight, and the treatment of 1.1 kg bread waste for all impact categories and indicators. For each mitigation action, relevant circularity indicators were tested. Based on this, the functionality and suitability of these indicators were discussed.Results and discussionFour of the circularity indicators were based on nitrogen (N) or phosphorus (P) substances: N recycling index, partial N balance, consumption of fossil-P fertilizers, and emissions to water bodies (P). Even if the indicators do not capture the impact of emissions of N and P as the eutrophication impact categories, they provide a useful indication of the circularity of a system. The other three circularity indicators tested were as follows: renewable energy production, soil organic carbon, and land use ratio. The renewable energy production indicator is easy to understand and communicate and provides unique information. Soil organic carbon presents a potential for soil carbon sequestration. Land use ratio is based on the same data as land occupation but provides an assessment of whether feed production competes for the suitable area for food production by including production of human-digestible protein.ConclusionsCircularity indicators provide valuable information about the circularity of an agricultural product system. The circularity indicators and LCA impact categories can be used either separately or together, or to complement each other. The choice of indicators depends on the questions raised, i.e., goals and scope, and it is therefore important to have a number of circular indicators to choose from in order to achieve a comprehensive assessment.

Keywords

LCA; Circular economy; Circularity indicators; Pork production; Agriculture; Mitigation actions

Published in

International Journal of Life Cycle Assessment
2023,
Publisher: SPRINGER HEIDELBERG

SLU Authors

• Röös, Elin

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

End hunger, achieve food security and improved nutrition and promote sustainable agriculture
Ensure sustainable consumption and production patterns


UKÄ Subject classification

Animal and Dairy Science
Economics


Publication identifier

DOI: https://doi.org/10.1007/s11367-023-02150-4

Permanent link to this page (URI)

https://res.slu.se/id/publ/121905