Integrating ecosystem services provided by legumes in agricultural life cycle assessment (LCA): A review of methodologies

• Legumes ecosystem services (ES) must be integrated into life cycle assessment (LCA). • Regulation & Maintenance services present the most fragmented knowledge. • Regulation of carbon cycling and field emissions are currently assessed in LCA. • Biodiversity, pollination, and pest control ES lack a standardized methodology. • Most ES urgently need harmonization and/or methodological development. Agricultural production is endangering agroecosystems health and functioning, compromising the delivery of many ecosystem services (ES) to prioritize provisioning. Legumes’ inclusion in cropping systems appears as a promising solution towards the ecological intensification of agriculture in Europe, providing a multiplicity of ES. Agricultural Life Cycle Assessment (LCA) does not explicitly assess ES; however, the potential benefits offered by an improved representation of agroecosystem processes reveal an urgent need for ES integration into LCA. Through a systematic review of scientific literature, we collected a list of methods applied to assess legumes ES in European conditions. Methods were grouped following the Common International Classification of Ecosystem Services (CICES) and through general ES definitions. At the end of the process, 148 methods were found, of which: 81.8% were associated with Regulation & Maintenance services; 8.1% to Provisioning services; and 10.1% described methods related to the combination of different CICES sections. No methods for Cultural services were found. Most of the methods were based on direct measurements, except for those ES already part of the current LCA frameworks. The Regulation & Maintenance section is the area with the most fragmented knowledge, with some ES presenting well-established methodologies (e.g. climate change buffering and leaching regulation) and others which are currently not fully integrated into LCA, such as biodiversity maintenance, pest control, and pollination. Future research should focus on LCA methodologies for the integration of emerging agriculture-related ES. Achieving more comprehensive LCA is necessary to improve the understanding of legumes’ role in maintaining agroecosystems functionality.