Effects of Different Cultivated Land Utilization Types on Heavy Metal Characteristics and Microbial Community...

Area of Science:

• Environmental Science
• Soil Science
• Microbiology

Background:

• Naturally high heavy metal content in soil poses environmental challenges.
• Cultivated land use can influence heavy metal migration and soil microbial community structure.
• Understanding these interactions is crucial for soil health management.

Purpose of the Study:

• To analyze soil heavy metals and microbial community structure in diverse cultivated land types.
• To elucidate the assembly mechanisms and driving factors of bacterial community changes.
• To assess the impact of land use on heavy metal contamination and soil health.

Main Methods:

• Collected 96 topsoil and 20 soil profile samples from bare land (CK), corn (COR), paddy (RIC), and vegetable (VEG) soils.
• Analyzed heavy metal concentrations (As, Cd, Cr, Pb, Zn).
• Assessed bacterial diversity using Shannon, Chao1, and ACE indices.
• Utilized Principal Coordinate Analysis (PCoA) and Non-metric Multidimensional Scaling (NMDS) for community analysis.

Main Results:

• Corn (COR) soils showed the highest levels of available As, Cd, Cr, Pb, and Zn, with significant Cd contamination.
• Paddy (RIC) soils exhibited the highest bacterial diversity.
• Proteobacteria was the dominant bacterial phylum across all agricultural soils.
• Soil pH, organic matter (OM), and heavy metals (Cd, Pb, Zn) were key drivers of bacterial community shifts.

Conclusions:

• Cultivated land use significantly alters heavy metal migration and soil bacterial community composition.
• Specific land use types (e.g., COR, RIC) differentially affect heavy metal levels and microbial diversity.
• Findings provide valuable insights for managing soils in areas with naturally high heavy metal content.