Organic Amendments Regulate Soil Bacterial Diversity and Cooperative Network Structure in Reclaimed Coal Gangue Soil

TL;DR

This study explores how different organic amendments affect soil bacteria in reclaimed coal gangue soil, finding that combinations like RAE and manure enhance microbial cooperation and diversity.

Contribution

The study reveals how RAE-based amendments, especially with manure, improve microbial functionality in degraded coal gangue soils.

Findings

Manure increased bacterial diversity and favored taxa involved in organic matter transformation.

RAE combined with manure enhanced network connectivity and positive microbial interactions.

RAE with Trichoderma reduced diversity and simplified microbial networks.

Abstract

Restoring soil microbial functioning in reclaimed coal gangue soils is critical for ecosystem recovery, yet how different organic amendments, particularly industrial by-products, regulate bacterial communities remains unclear. Here, we tested three organic inputs—the residue after evaporation (RAE) from vitamin C production, Trichoderma inoculation, and cattle manure—applied alone and in combination in a photovoltaic agroforestry system on coal gangue spoil. Our results indicate that the treatment based on manure increased bacterial α-diversity and favored taxa associated with organic matter transformation, including Actinobacteria and Acidobacteriota, suggesting expanded niche partitioning in response to heterogeneous substrates and nutrients. RAE alone supported communities closer to non-manure controls but, when co-applied with manure, further enhanced network connectivity and the prevalence of positive associations, indicating strengthened cooperative interactions and functional redundancy. In contrast, RAE combined with Trichoderma in the absence of manure reduced diversity, and simplified the co-occurrence network, suggesting resource monopolization and antagonism. Overall, RAE acted as a key driver of microbial cooperation and potential ecosystem resilience, and RAE-based amendments, particularly when integrated with manure, appear to be effective strategies for improving soil microbial functionality in degraded coal gangue soils.

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