Metagenomics analysis of the effects of long-term stand age on beneficial soil bacterial community structure under Chinese ancient mulberry farming practice

The ecological distribution and activities of soil microbes can reflect the influence of environmental factors on microbes and changes in soil fertility. Understanding the community structure of the soil microbes is of great importance to maintaining soil health in ancient mulberry plantation ecosystems. In this study, the population structure of soil microorganisms in different ages of mulberry plantations was analyzed using high-throughput sequencing technology. A total of 1616, 1568, 1379 and 1477 operational taxonomic units were acquired from samples of 3Y (3-year-old), 35Y (35-year-old), 200Y (200-year-old) and 600Y (600-year-old) soils, respectively. The results exhibited that the highest community diversity was found in 35Y soil, followed by 200Y soil, and showed that the stand age strongly influenced the community structure of soil bacteria. A total of 23 phyla were detected in 12 samples, and the genus of bacteria that predominated the different stand ages mainly included; Phenylobacterium, Cohnella, Lactococcus, Sphingomonas, Bacillus, and Microbispora. The relative abundance of Phenylobacterium accounts for 22.6–53.5% of the total abundance. This study showed that the richness and diversity of the soil bacteria decreased as the stand age increased in ancient mulberry plantations.