Soil pollution and degradation are threatening food security, crop productivity, and the long-term health of agricultural land worldwide. A new review published in Biochar suggests that one promising solution may come from pairing two powerful natural tools: biochar and beneficial microbes .
The review, titled “Biochar immobilized microbes for sustainable soil remediation and agriculture enhancement: from lab to farmland,” examines how biochar-immobilized microbes, also known as BIMs, can help clean contaminated soils, improve soil health, and support crop growth. By analyzing evidence from 92 published studies , including 85 pot experiments and 11 field applications , the authors provide a data-driven overview of how this technology works and what is needed to bring it closer to practical use on farms.
Biochar is a carbon-rich material made by heating plant or organic biomass under limited oxygen. It has a porous structure, high surface area, and many chemical binding sites, making it useful for holding water, retaining nutrients, and trapping pollutants. Beneficial microbes, meanwhile, can transform contaminants, cycle nutrients, produce growth-promoting compounds, and help plants tolerate stress. When microbes are attached to biochar, the biochar acts like a protective home and delivery vehicle, helping microbes survive longer and function more effectively in soil.
“Biochar can provide shelter, nutrients, and attachment sites for functional microbes, while microbes add biological activity that biochar alone cannot provide,” said the study authors. “Together, they create a synergistic system for soil restoration and sustainable agriculture.”
The review summarizes four major ways to attach microbes to biochar: adsorption, entrapment, covalent bonding, and crosslinking . Adsorption is simple and cost-effective, while chemical approaches can provide stronger attachment and greater stability. The best method depends on the target application, cost, microbial survival, and field conditions.
Across the studies reviewed, BIMs showed strong potential to improve soil quality. They were reported to increase soil pH, enhance cation exchange capacity, support soil enzymes such as urease and dehydrogenase, and improve nutrient availability. These changes can create a healthier root zone and a more active microbial community.
The review also found that BIMs can help remediate both inorganic and organic pollutants. Reported remediation efficiencies reached up to about 95% for heavy metals and about 90% or more for organic pollutants in some cases. The authors explain that biochar can first adsorb and concentrate contaminants, while attached microbes can transform or degrade them, forming a useful adsorption, degradation, and regeneration cycle.
For agriculture, BIMs also showed encouraging results. Field applications indicated that BIMs could increase crop yields, with some studies reporting gains of up to 45% or higher , mainly through improved nutrient cycling, root development, stress tolerance, and pathogen suppression. In the reviewed dataset, BIMs generally performed better than biochar alone or microbial inoculants alone.
However, the authors caution that most evidence still comes from controlled pot experiments rather than long-term field trials. In real farmland, microbial survival can be affected by rainfall, drought, temperature changes, soil type, competition from native microbes, and farming practices. Application rate, incorporation depth, timing, and compatibility with farm machinery also remain insufficiently standardized.
“The next step is not only to prove that BIMs work, but to determine how farmers can use them reliably, affordably, and safely under real field conditions,” the authors said.
The review calls for more long-term field validation, lifecycle assessment, dose-effect-cost modeling, and farmer-centered optimization. If these challenges can be addressed, biochar-immobilized microbes may offer a practical pathway to restore contaminated soils, improve crop productivity, and support more sustainable agriculture .
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Journal Reference: Li, X., Lyu, Q., Han, C. et al. Biochar immobilized microbes for sustainable soil remediation and agriculture enhancement: from lab to farmland. Biochar 8 , 107 (2026).
https://doi.org/10.1007/s42773-026-00613-z
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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Biochar
Literature review
Biochar immobilized microbes for sustainable soil remediation and agriculture enhancement: from lab to farmland
8-Jun-2026