A new study reveals how manganese-modified biochar helps beneficial fungi break down agricultural residues and accelerate the formation of valuable humic substances, offering a promising approach to sustainable organic waste recycling and soil improvement.
Agricultural residues such as wheat straw are produced in enormous quantities worldwide. Although these materials contain valuable organic carbon, their tough plant fibers resist decomposition, making efficient recycling a major challenge. Now, researchers have discovered that combining manganese-modified biochar with white-rot fungi can significantly improve the conversion of agricultural waste into humic substances, which are essential for soil fertility, carbon cycling, and ecosystem health.
The study, published in Biochar, demonstrates that this combination accelerates the breakdown of plant materials while promoting the formation of more complex and stable organic compounds.
"Agricultural waste is not simply something to dispose of. It is a valuable carbon resource that can be transformed into materials that support healthier soils," said the research team. "Our findings reveal how manganese-modified biochar can work together with beneficial fungi to make this transformation more efficient."
Humic substances are important components of soil organic matter. They help improve soil structure, support nutrient retention, and regulate carbon cycling. However, their natural formation is slow. Accelerating this process, known as humification, could provide new opportunities to recycle agricultural residues into valuable soil amendments.
To investigate this possibility, researchers combined manganese-modified biochar, produced from bamboo-derived biochar, with the white-rot fungus Phanerochaete chrysosporium. They then conducted a 35-day fermentation experiment using wheat straw.
The results were striking. With 5% manganese-modified biochar, lignin degradation increased by 93.4%, cellulose degradation by 77.0%, and hemicellulose degradation by 30.9% compared with the fungus-only control. Even more importantly, humic acid content increased by 47.7%, while an indicator of humic substance polymerization rose by 112.4%.
These improvements suggest that the treatment not only accelerates plant fiber decomposition but also promotes the formation of more complex humic materials.
To understand the underlying mechanisms, the researchers combined advanced molecular analysis, interpretable machine learning, and multi-omics techniques.
They discovered that manganese-modified biochar enhances fungal growth and stimulates enzymes responsible for breaking down resistant plant fibers. Manganese-associated oxidation reactions also contribute to this process, helping release smaller organic molecules that serve as building blocks for humic substances.
Molecular analysis further revealed that the treatment promotes specific chemical transformations, including deamination, dealkylation, and lignin breakdown. These changes favor the formation of more aromatic, oxygen-rich, and structurally complex humic-like substances, particularly through pathways involving polyphenols and quinones.
Meanwhile, gene expression and metabolite analyses showed enhanced activity in pathways associated with plant fiber degradation and the production of humification precursors.
Together, these findings reveal a coordinated process in which biochar, manganese, and fungi work synergistically to accelerate organic matter transformation.
The researchers believe this strategy could support more efficient recycling of lignocellulose-rich agricultural wastes and the development of sustainable soil amendment technologies.
However, further research is needed to evaluate manganese release, long-term environmental safety, and economic feasibility under practical operating conditions.
By uncovering the molecular mechanisms behind accelerated humification, this study provides a scientific foundation for transforming agricultural residues into valuable organic resources and advancing sustainable waste management.
===
Journal Reference: Wang, F., Zhang, L., Zhou, F. et al. Manganese-modified biochar enhances white-rot fungi-mediated lignocellulose humification: insights from molecular transformation and multi-omics analyses. Biochar 8, 140 (2026).
https://doi.org/10.1007/s42773-026-00659-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.
