Long-Term Legume Cultivation Affects the Soil Bacterial Community via Altering the Soil Pore Structure in Coal Mine Reclamation Agroecosystems.

Legume cultivation has great potential for improving soil microbial communities and soil quality in reclaimed ecosystems. However, little is known about the effects of long-term legume cultivation on the soil microbial community structure in agroecosystems in coal mine reclamation areas. To address this issue, we used metagenomics to examine the variations in the soil bacterial community composition and functionality under three leguminous crops in a 10-year reclamation experiment. After 10 years, we found dissimilarity in the microbial communities between the control and leguminous crops. Furthermore, three legume cultivation greatly promoted the diversity and abundance of the dominant bacteria The keystone phyla of the soil bacterial communities in the reclamation area included Proteobacteria, Acidobacteriota, Gemmatimonadota and Myxococcota. In particular, soil pore structure was the main factor influencing the variation in the bacterial community. Therefore, long-term legume cultivation can significantly improve the soil microbial community structure, which likely serves as the basis for soil microbial abundance and functionality and soil health. This study confirmed the ability of the spongy structure formed by legumes to optimize resource use in a nutrient-impoverished mine reclamation agroecosystem. These findings may have important implications for assessing microbial multifunctionality in agroecosystems in coal mine reclamation areas.