Tailored biochar could transform how crops grow, resist disease, and clean polluted soils

Biochar has long been promoted as a climate-friendly soil amendment, but new research suggests that treating it as a one-size-fits-all solution may be limiting its full potential. A new open-access review published in Biochar shows that engineered biochar works best when it is carefully customized for specific agricultural and environmental goals, from boosting crop yields to suppressing soil-borne diseases and remediating contaminated land.

The international research team reviewed more than a decade of studies on engineered biochar and its interactions in the rhizosphere, the thin zone of soil surrounding plant roots where microbes, nutrients, and roots constantly interact. Their findings point to a major shift in how biochar should be designed and applied.

“Biochar is not just a passive soil additive,” said lead author Adnan Mustafa, a soil and environmental scientist. “When engineered correctly, it becomes an active architect of the rhizosphere, shaping nutrient availability, microbial communities, and even plant immunity.”

Biochar is a carbon-rich material produced by heating organic waste such as crop residues or manure in low-oxygen conditions. While traditional biochar has been widely studied for improving soil structure and storing carbon, engineered biochar is deliberately modified to perform specific functions. These modifications can include nutrient enrichment, microbial inoculation, surface functionalization, or the addition of antimicrobial or catalytic properties.

The review highlights three major application areas where purpose-specific biochar shows promise: crop production, crop protection, and soil remediation.

For crop production, nutrient-enriched and bioprimed biochars can improve the efficiency of nitrogen, phosphorus, and potassium use while supporting beneficial soil microbes. This can reduce reliance on synthetic fertilizers and help crops perform better under drought or nutrient-poor conditions.

“Matching biochar design with crop needs is essential,” said co-author Xiankai Lu. “A biochar optimized for nutrient release in a maize field may not be suitable for immobilizing heavy metals in polluted soil.”

In crop protection, engineered biochars with antimicrobial properties or those that stimulate plant defense responses can suppress soil-borne pathogens and reduce disease pressure. Some biochars can also trigger induced systemic resistance, a natural immune response that helps plants defend themselves against pests and diseases without chemical pesticides.

In contaminated soils, specially designed biochars can bind heavy metals and organic pollutants in the root zone, limiting their uptake by crops while allowing essential nutrients to pass through. This creates a protective buffer around plant roots, enabling safer food production on degraded land.

The researchers emphasize that these benefits often involve trade-offs. For example, biochars that strongly bind contaminants may also reduce nutrient availability if not carefully formulated. Biochar effects can also change over time as the material weathers and interacts with soil microbes.

“Understanding these trade-offs is critical for real-world applications,” said Mustafa. “Precision design and field-scale testing are needed to avoid unintended consequences.”

The review also identifies economic and practical challenges, including production costs, feedstock availability, and limited long-term field data. However, emerging innovations such as nano-enabled biochars, biochar-microbe partnerships, and integration with precision agriculture technologies offer new pathways forward.

By synthesizing current knowledge and proposing a functional classification framework, the authors provide a roadmap for researchers, farmers, and policymakers seeking to harness biochar for sustainable agriculture and environmental restoration.

“Tailored biochar has the potential to address food security, climate resilience, and soil degradation simultaneously,” said Lu. “But achieving that potential requires moving beyond generic solutions toward purpose-driven design.”

The study underscores that the future of biochar lies not in applying more of it, but in applying the right biochar in the right way for the right purpose.

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Journal Reference: Mustafa, A., Saeed, Q., Lu, X. et al. Beyond one-size-fits-all: tailoring engineered biochar for purpose-specific rhizosphere engineering in crop production, protection, and soil remediation. Biochar 8, 3 (2026).   

https://doi.org/10.1007/s42773-025-00521-8  

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About Biochar

Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field. 

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