Soil contamination by heavy metals such as cadmium (Cd) poses a growing threat to global food security and human health. A new study published in Biochar reports that combining arbuscular mycorrhizal fungi (AMF) with biochar can reshape soil microbiomes, reduce cadmium uptake, and dramatically improve plant growth, offering a sustainable strategy for farmland restoration.
The research team, led by scientists from Anhui Agricultural University, tested how AMF and rice husk–derived biochar interact to support plant growth in Cd-contaminated soils with different fertility levels. Using chive (Allium ascalonicum L.) as a model crop, they combined greenhouse experiments with advanced microbiome analyses to uncover the synergistic effects of these two soil amendments.
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Results showed that plants treated with both AMF and biochar had up to 320% greater shoot biomass compared with untreated controls, even under Cd stress. Remarkably, the combined treatment was especially effective in nutrient-poor soils, where plant height and root growth significantly improved despite high cadmium concentrations.
Rhizosphere microbiome
Further sequencing revealed that co-application reshaped the rhizosphere microbiome, increasing bacterial diversity and strengthening microbial networks. From Cd-contaminated soils, the team isolated 34 bacterial strains and designed synthetic microbial communities (SynComs) to mimic beneficial interactions. Among eight SynComs tested, one community (SC3), dominated by Bacillaceae and Sphingomonadaceae, boosted chive shoot biomass by 243% in barren soil and 350% in fertile soil, highlighting the potential of engineered microbial consortia to enhance plant resilience.
“Our findings show that biochar and AMF not only reduce cadmium toxicity but also foster a healthier soil microbiome,” said co-corresponding author Prof. Xiaoyu Li. “By integrating microbial ecology with soil amendments, we can develop practical solutions for safe crop production in contaminated farmland.”
Microbial–biochar partnerships
The study underscores the promise of microbial–biochar partnerships as eco-friendly alternatives to chemical remediation. By combining functional microbes, biochar’s porous carbon matrix, and symbiotic fungi, researchers envision a “trinity technology” that could be scaled up for field applications to safeguard food production in polluted regions.
“Cadmium pollution is a persistent agricultural challenge, but our work demonstrates a pathway toward sustainable remediation,” added co-author Prof. Jin Chen. “Next, we plan field trials to optimize microbial formulations and test their long-term stability under real farming conditions.”
This research offers critical insights for policymakers, farmers, and scientists working to restore degraded soils and strengthen global food security under the pressures of industrial pollution.
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