Circular Bioeconomy Synergies: Unlocking Plant Biostimulant Potential for Regenerative and Resilient Food Systems

Plant biostimulants are increasingly recognized as pivotal instruments for advancing sustainable agriculture, driven by the urgent need to enhance crop resilience, resource efficiency, and environmental stewardship. They support nutrient uptake and nutrient use efficiency, boost plant tolerance to abiotic stresses, and contribute to improved crop quality. The circular bioeconomy represents a transformative pathway based on cycling models by which biological resources are renewed, biomass side-streams become feedstocks, and natural ecosystems are protected. This transition relies on strengthening rural–urban linkages, where organic waste streams from cities are reintegrated into agricultural production systems. The circular bioeconomy helps reduce resource scarcity, soil and ecosystem degradation, and limits climate change. It also enhances food system sustainability by closing nutrient loops between agriculture, processing, and consumption, resonates with agroecological principles and can be enriched by Traditional Ecological Knowledge (TEK) systems.The prevailing model of the circular bioeconomy, built around integrated biorefinery systems, faces substantial structural challenges. High initial capital requirements, insufficient infrastructure for side stream harvesting and storage, complex logistics systems, and fragmented regulatory environments hinder large scale deployment. Additional obstacles involve limited technological maturity, competition with existing utilization of the biomass side-streams, and the need to change consumer behavior and industry practices toward sustainable, regenerative models. Within this context, closing the loop of the circular bioeconomy through plant biostimulants offers a compelling pathway. Valorizing biomass side streams into high-value agricultural inputs enhances soil health and carbon sequestration, water regulation, crop quality, and resource efficiency while reducing waste and strengthening rural economies. Within agroecological transition pathways, plant biostimulants derived from bioeconomy side streams can act as key enablers of low-input, biodiversity-based farming systems, particularly when combined with TEK on soil fertility management, plant health, and resource cycling, reconnecting scientific innovation with culturally embedded knowledge systems.However, despite their promise, the widespread adoption of biostimulants remains constrained by inconsistent field performance and persistent regulatory bottlenecks. Current regulatory definitions, centered primarily on agricultural function, tend to discourage deeper investigation into mechanisms of action, thereby limiting progress toward reproducible efficacy and more coherent regulatory frameworks.This Research Topic explores recent advances in converting diverse bioeconomy side streams into plant biostimulants that align with circularity principles and reinforce sustainable food systems. It considers laboratory characterization, pilot scale valorization, and field level validation.The Research Topic places particular emphasis on elucidating mechanisms of action of side-stream biostimulants, improving feedstock sourcing strategies, and developing small scale or mobile biorefinery units that enable localized biostimulant production, formulation innovation for efficient utilization, and value chain integration. Transdisciplinary contributions are encouraged: industrial symbiosis models in rural regions, environmental and socio economic assessments, Living Labs (LL), multi-actor governance, agroecological practices, TEK-informed approaches, and plant-science based evidence that support policy pathways for a safe, effective, and scalable valorization of bioeconomy side streams, and integration of biostimulants into regional bioeconomy systems.We welcome submissions addressing, but not limited to, the following themes:• Mechanisms of action of plant biostimulants derived from bioeconomy side streams• Strategies to compensate for feedstock variability and contaminants to ensure reproducible bioproducts• Formulation approaches and shelf stability enhancement for side stream derived biostimulants• Role of urban and peri-urban bio-waste streams in circular biostimulant production systems• Ecosystem service assessment of side-stream biostimulants across scales (plot to landscape)• Integration of TEK and farmer-led innovations in the development and application of side-stream biostimulants• Role of side-stream biostimulants in supporting agroecological transitions • Co-creation, participatory experimentation, and LL approaches• Integrated solutions for consistent field efficacy and the advancement of harmonized standards that clarify regulatory frameworks and contribute to governance models Topic editors: Diana Constantinescu-Aruxandei, Ina Säumel, Lina Raudonė, Florin Oancea Source: https://www.frontiersin.org/research-topics/79846/circular-bioeconomy-synergies-unlocking-plant-biostimulant-potential-for-regenerative-and-resilient-food-systems