Rare Taxa as Key Drivers of Soil Multi-Nutrient Cycling Under Different Crop Types

Area of Science:

• Soil microbiology
• Agricultural ecology
• Nutrient cycling

Background:

• Soil microorganisms are vital for nutrient cycling, with distinct roles for abundant and rare taxa.
• Understanding how soil microbes influence nutrient cycling under various crop types is crucial but remains unclear.

Purpose of the Study:

• To investigate the network structure, diversity, and microbial composition in croplands of the Yellow River Delta.
• To elucidate the distinct roles of abundant and rare soil microbial taxa in nutrient cycling across different crop types (soybean, maize, cotton, sorghum).

Main Methods:

• Analysis of soil microbial community structure and diversity.
• Investigation of co-occurring network structures.
• Application of structural equation modeling to assess relationships between microbial diversity and nutrient cycling.

Main Results:

• Sorghum planting-soils showed greater co-occurring network complexity.
• Cotton-planting soil exhibited the highest bacterial alpha diversity, sensitive to environmental changes.
• Rare taxa diversity strongly correlated with critical soil nutrients and significantly influenced the soil multi-nutrient cycling index (MNC), with contrasting effects between bacteria and fungi.
• Soil organic carbon and total nitrogen were identified as key factors affecting rare bacterial and fungal diversity.

Conclusions:

• Rare soil microbial diversity plays a significant role in driving variations in nutrient cycling expression within agricultural ecosystems.
• Abundant taxa are crucial for overall soil multi-nutrient cycling, while rare taxa are key regulators of nutrient cycling dynamics.
• Specific crop types influence soil microbial diversity and its relationship with nutrient cycling, highlighting the need for crop-specific management strategies.