Alignment between product-based regulation and soil process-based functions in biochar systems under EU policy

As biochar transitions from a niche soil amendment to a component of carbon dioxide removal (CDR) strategies, its governance has largely developed within product-based regulatory frameworks. This article synthesises soil science evidence to assess the extent to which current regulatory approaches are aligned with soil processes, heterogeneity, and long-term soil functioning. We argue that prevailing frameworks, exemplified by the EU Fertilising Products Regulation (FPR) 2019/1009 and illustrated through its national implementation in Portugal, assess biochar as a standardised input, despite its role as a persistent and soil-dependent amendment. This framing positions biochar primarily as a discrete material rather than as an intervention whose function emerges through interactions with soil physical, chemical, and biological processes over time. By analysing the interface between waste, product, and soil-related legislation, we highlight how regulatory pathways—particularly those related to waste classification and End-of-Waste procedures—may influence the deployment of biochar in Mediterranean contexts. We conclude by outlining elements of a soil-informed governance approach that complements existing frameworks by better integrating soil processes, hydrological function, and long-term soil resilience.