Surface-engineered biochars enhance soil fertility by modulating microbial assembly and ecological network stability.

Area of Science:

• Soil Science
• Environmental Microbiology
• Agricultural Chemistry

Background:

• Low-fertility soils impede sustainable agriculture and soil health.
• Biochar amendments are explored for soil improvement, but surface modification effects on microbial ecology are less understood.

Purpose of the Study:

• To investigate the impact of surface-engineered biochars (acid-modified, alkali-modified, magnetically modified) on microbial communities and soil nutrient functions in low-fertility sandy loam.
• To elucidate the mechanisms by which modified biochars enhance soil fertility and microbial ecological stability.

Main Methods:

• Surface modification of biochar (acid, alkali, magnetic) and characterization of physicochemical properties.
• Application of modified biochars to low-fertility soil and assessment of soil properties (pH, organic matter, nutrients).
• High-throughput sequencing for bacterial and fungal community analysis, co-occurrence network analysis, and structural equation modeling.

Main Results:

• Modified biochars significantly improved soil pH, organic matter, and nutrient availability, enhancing the Soil Function Index.
• Biochar amendments altered microbial community structure, shifting assembly from stochastic to deterministic processes.
• Increased network modularity and synergistic interactions among microbial taxa were observed, promoting ecological stability.

Conclusions:

• Surface-engineered biochars effectively modulate soil microbial communities and enhance nutrient cycling in low-fertility soils.
• Microbial community restructuring and network dynamics are key mechanisms mediating biochar-induced soil functional improvement.
• Functionalized biochars offer a promising strategy for improving soil quality and agricultural productivity in nutrient-depleted systems.