Mechanism of bacterial community construction in typical red paddy soil

Rice is one of the important food crops cultivated by human beings, and sufficient water is required during the rice growth period, which is significantly different from dryland soil, and long-term rice planting forms a proprietary paddy soil type
.
Grain is stored in the soil, and soil fertility is an important determinant
of crop yield.
Microorganisms that inhabit the soil are the key to driving soil nutrient turnover, microorganisms are everywhere, and environmental selection is an important factor
in determining the construction of microbial communities.
How is the microbial community built in paddy soil, and what are the driving factors? This key scientific question remains to be answered
.

Li Weitao, an assistant researcher and collaborator of the Biological Invasion Research Group of Banna Botanical Garden, selected a typical red loam paddy soil in Jiangxi, collected soil in layers, and analyzed the diversity and abundance of
bacterial communities by means of high-throughput sequencing and fluorescence quantitative PCR technology.
Calculate βNTI values based on zero model to resolve the mechanism
of bacterial community construction.
The study found that the construction of bacterial communities in the upper surface soil (0-10 cm) was mainly a random process, with long-term flooding of paddy soil and migration of microorganisms with water currents, resulting in relative uniformization
of microbial community structure.
As the depth of the soil layer increases, the limitation of microbial diffusion becomes more obvious, especially in the underlying soil (20-40 cm), and the microbial community structure is more closely
related to the matrix that forms the soil.
The 10-20 cm soil layer resembles a "corridor", and microorganisms "migrate" downward from the topsoil
.
With the increase of soil depth, nutrients become more and more barren, microbial diversity decreases, and the intensity of interaction between microorganisms increases, and nutrient and microbial interaction are the key factors
affecting the construction of microbial communities.
By collecting soil samples at different soil depths, this study reveals the mechanism of bacterial community construction, enriches the important theories of microbial ecology, and provides an important reference
for soil science research.

The results were published in the journal Soil Biology and Biochemistry under the title Depth effects on bacterial community assembly processes in paddy soils
.
The research was supported
by the National Natural Science Youth Fund.

Figure 1.
Construction of bacterial communities in different soil layers

Figure 2.
Network topologies co-occur with bacteria in different soil layers

Figure 3.
Direct and indirect effects of soil physicochemical and species interaction on βNTI