Effects of mulching on soil bacterial community in the small- to medium-diameter Phyllostachys edulis plantation

By high- throughput sequencing on Illumina Miseq platform and bioinformatics, changes of soil bacterial communities in a small- to medium-diameter Phyllostachys edulis plantation subjected to different soil management practices (mulching, alternate operation, and long-term mulching) were analyzed to investigate the mechanism of soil bacterial community variation and its effect on soil degradation of mulched P. edulis plantation. The results showed that soil subjected to four different soil management practices (CK, mulching, alternate operation, and long- term mulching) contained a wide diversity of bacterial communities covering 26 phyla, 69 classes, 118 orders, and 197 genera. Among them, Acidobacteria were the dominant in all four plots (30.85%-44.22%), followed by Proteobacteria (8.23%-25.41%), Chlorobacteria (2.48%-7.91%), Verrucomicrobia (2.39%-6.82%), AD3 (1.05%-15.18%), Actinobacteria (3.99%-8.39%) and TM7 (0.61%-6.68%). Soil total nitrogen and total organic carbon of all the three treatment sample plots were higher than those of the CK. The soil pH of the sample plots of mulching, alternate operation, and long-term mulching significantly decreased, and the soil became more acidic as the mulching period was prolonged. α-diversity and principal co-ordinate analysis showed that mulching had a greater impact on the diversity and structure of the soil bacterial community, and increased the number, species and abundance of bacteria. The shallow tillage of soil surface under the mulching prevented mechanical disturbance of the soil, thus forming a 0-20 cm thick layer of semi-decomposed organic matters within a short period of time to provide energy sources for bacterial reproduction. The alternate operation plot showed the greatest number, species and abundance of bacteria. However, the long-term mulching plot showed a decrease in the number, species and abundance of bacteria, as well as a significantly lower Chao1 index than the CK. This study provides technical support and data reference for research on orientation cultivation of low-yield bamboo and ecological restoration technology of bamboo forest.