From pore to policy: Evolution of the biochar–plant–soil–environment matrix for remediation, microbiome synergies, biogeochemical cycling, and the circular bioeconomy

Biochar has gained global attention as a multifunctional material for carbon sequestration, pollutant remediation, soil restoration, and climate change mitigation. However, most current studies focus on freshly produced biochar under short-term experimental conditions, leaving major uncertainties regarding its long-term environmental behavior and ecosystem-scale impacts. As biochar ages in soil through wetting–drying cycles, salinity, oxidation, and temperature fluctuations, its pore structure, surface chemistry, and redox properties evolve significantly. These transformations influence plant growth, microbial activity, nutrient cycling, contaminant mobility, greenhouse gas emissions, and hydrological processes. Understanding the dynamic interactions within the biochar–plant–soil–environment matrix is therefore essential for predicting long-term ecosystem responses and designing sustainable remediation strategies. This Research Topic adopts a holistic “Pore to Policy” framework that connects microscale mechanisms with macroscale environmental management, emphasizing the integration of environmental science, microbiology, engineering, and policy to support circular bioeconomy transitions and sustainable land-use practices.

This Research Topic aims to address critical knowledge gaps regarding the long-term evolution, functionality, and environmental implications of biochar within natural and engineered ecosystems. While biochar is increasingly promoted for carbon dioxide removal, remediation, and sustainable agriculture, limited understanding exists on how aging processes alter its physicochemical properties and ecological interactions over time. Environmental stressors such as salinity, fluctuating moisture, temperature changes, and oxidation can significantly modify biochar surfaces, influencing microbial colonization, nutrient retention, contaminant transformation, and greenhouse gas dynamics.

The goal of this collection is to advance mechanistic understanding of the biochar–rhizosphere–microbiome nexus and its role in regulating biogeochemical cycling, ecosystem resilience, and environmental remediation. Particular emphasis is placed on interactions among soil, plants, microbes, water systems, and atmospheric processes. We also seek studies exploring how engineered and aged biochar materials facilitate electron transfer, biodegradation pathways, and immobilization of heavy metals and emerging contaminants such as PFAS, pharmaceuticals, and microplastics.

Beyond mechanistic science, this Research Topic aims to bridge research and policy by encouraging contributions on Life Cycle Assessment, carbon accounting, techno-economic analysis, and frameworks supporting circular bioeconomy implementation, climate mitigation strategies, and sustainable environmental management.

This Research Topic welcomes interdisciplinary contributions examining the evolution and environmental functionality of the biochar–plant–soil–environment matrix across terrestrial and aquatic systems. Topics of interest include, but are not limited to, biochar aging and surface transformation; rhizosphere and microbiome interactions; microbial communication and metabolic adaptation; nutrient cycling and greenhouse gas emissions; contaminant degradation and immobilization mechanisms; fate and transport of emerging contaminants; hydrological and ecosystem feedbacks; and biochar applications for remediation and sustainable agriculture.

We also encourage submissions addressing engineered biochar materials, electron transfer processes, biodegradation pathways, carbon sequestration, Life Cycle Assessment, carbon accounting, techno-economic analysis, and policy frameworks supporting circular bioeconomy transitions and sustainable land management.

The Research Topic welcomes original research articles, review papers, mini-reviews, perspectives, and methodological studies. Contributions should demonstrate scientific novelty, mechanistic insight, interdisciplinary relevance, or strong application potential in environmental science, microbiology, engineering, material science, or sustainability policy.

Article types and fees

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Data Report
• Editorial
• FAIR² Data
• Hypothesis and Theory
• Methods
• Mini Review
• Opinion
• Original Research
• ... View all formats

Articles that are accepted for publication by our external editors following rigorous peer review incur a publishing fee charged to Authors, institutions, or funders.

Article types

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Data Report
• Editorial
• FAIR² Data
• Hypothesis and Theory
• Methods
• Mini Review
• Opinion
• Original Research
• Perspective
• Policy and Practice Reviews
• Policy Brief
• Review
• Systematic Review
• Technology and Code

Keywords: Agirultural, Biochar, Crop yield, Nutrient cycling, Soil microbiology, Waste management

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.