Biochar Application Alleviated Negative Plant-Soil Feedback by Modifying Soil Microbiome.

Area of Science:

• Agricultural Science
• Soil Science
• Microbiology

Background:

• Negative plant-soil feedback (NPSF) hinders agricultural sustainability and causes replant failure.
• Biochar application is a potential strategy for soil improvement and mitigating NPSF, but its mechanisms are not fully understood.

Purpose of the Study:

• To investigate the effects of biochar amendment on NPSF in a sanqi (Panax notoginseng) production system.
• To elucidate the role of soil microorganisms in mediating biochar's impact on NPSF.

Main Methods:

• High-throughput sequencing was used to analyze bacterial and fungal communities in biochar-amended and unamended soils.
• Soil chemical properties (pH, EC, OM, AP, AK, C/N ratio) were measured.
• Correlation analyses were performed to link soil properties, microbial communities, and NPSF mitigation.

Main Results:

• Biochar amendment significantly alleviated NPSF and altered soil microbial communities, with bacteria being more sensitive than fungi.
• Bacterial diversity increased with biochar, while fungal diversity showed no significant change.
• Biochar improved soil chemical properties and enriched beneficial bacteria (e.g., Bacillus, Lysobacter) while suppressing pathogens (e.g., Fusarium, Ilyonectria).

Conclusions:

• Biochar application effectively mitigates NPSF by modifying the soil microbiome.
• The mechanism involves enriching beneficial microbes with antagonistic properties and suppressing soil-borne pathogens.
• Biochar's positive effects are linked to improved soil chemical properties and enhanced beneficial microbial populations.