Circular Economy in Agriculture—Review of Concepts, Practices, and Policy Implications

The circular economy (CE) has gained increasing attention as a framework for improving resource efficiency and sustainability in agricultural systems. However, circular agriculture remains an evolving field characterized by conceptual diversity, heterogeneous practices, and different assessment approaches. This review examines its conceptual foundations, practical applications, and policy implications through combined bibliometric and qualitative thematic analysis. Following a structured literature search and screening process, 462 publications were analyzed using VOSviewer to identify the thematic structure and evolution of the field. The bibliometric analysis reveals a research landscape dominated by nutrient cycling, waste management, resource recovery, and environmental sustainability, while economic, social, governance, and implementation dimensions remain comparatively less developed. The qualitative synthesis shows that nutrient and biomass recycling, integrated farming systems, and resource-efficient and digital technologies can support resource circularity, although their sustainability outcomes are context-dependent. Importantly, greater circularity does not necessarily imply greater sustainability due to potential economic, environmental, technological, and system-level trade-offs. Future research should prioritize multidimensional assessment frameworks, long-term empirical evidence, economic and social performance, and governance conditions for implementation. Circular agriculture should ultimately be evaluated by whether resource recirculation generates measurable and lasting sustainability benefits.