[Effects of Different Plantation Type on the Abundance and Diversity of Soil Microbes in Subtropical Red Soils].

Soil microbe plays an important role in carbon cycling, however, the effect of land use on soil microbe remain unclear. In present study, soil samples were collected from a long-term field experiment (Pantang Agroecosystem) in subtropical China (established in 1989), including paddy-rice (PR), upland-crop (UC), and paddy rice-upland crop rotation (PU) on soil bacterial (bacteria and Archaea) community structures. The effects of long-term different land uses were determined using terminal restriction fragment length polymorphism (T-RFLP) and quantitative PCR (RT-PCR) of the 16S rRNA gene. The abundance of soil microbial 16S rRNA genes ranged from 2.5 x 10(9)-1.5 x 10(10) copies x g(-1) dry soil. Compared with the PR, UP and UC led to a significant reduction in 16S rRNA genes abundance (P < 0.05). The soil microbial communities were dominated by bacteria such as Proteobacteria (76 and 90 and 327 bp; relative abundance of 47% - 53%) and Chloroflexi (65 bp; relative abundance of 10% - 12%). RDA statistical analyses demonstrated that there were significant differences in the microbial community composition in PR, UC, and PU treated soils. Soil organic carbon and total nitrogen content were the most highly statistically significant factors which positively influenced the soil microbial population. Taken together, our findings prove the long-term different land uses significantly influence the microbial diversity and community structure. The rice planting is an effective way of sustainable utilization of subtropical red soil, and it is more advantageous to the accumulation of soil organic matter, soil fertility and microbial diversity.