Cold waterlogged paddy field is a type of low-yield paddy
soil, and opening a drainage ditch has been suggested to
improve waterlogged paddy soil and to increase the rice yield.
However, little has been done on the role of a drainage ditch in
ameliorating waterlogged soil. In the present study, rice (
Oryza sativa
L.) yield, soil physicochemical properties, microbial
abundances and community structures in the surface soil of a
cold waterlogged paddy field, which has three treatments with
different distances from a drainage ditch including 5, 15 and
25 m were investigated. The results showed that opening a
drainage ditch had a significant effect on the rice yield and soil
physicochemical properties. Sampling sites near the drainage
ditch such as 5 m-site had higher yield and soil nutrients,
however, 25 m-site had lower values. Bacterial 16S rRNA
gene did not exhibit a regular pattern but fungal abundance
decreased sharply with increasing distance from the drainage
ditch. The most abundant bacterial phyla across all soil
samples were
Proteobacteria,
Acidobacteria,
Planctomycetes
and
Chloroflexi. Abundant fungal phyla were
Ascomycota,
Zygomycota and
Basidiomycota. Three treatments had similar
microbial community compositions but with different relative
abundances. The Bray-Curtis distance demonstrated that
microbial community structures were divided into two major
groups, samples of 5 m- and 15 m-site clustered into one
group and samples of 25 m-site was another group. Moreover,
redundancy analysis revealed that soil redox potential and
total reducing substances were significant factors in shaping
microbial community structures. The abundant aerobic
bacteria were observed at the 5 m- and 15 m-site, in contrast,
abundant anaerobic bacteria were observed at the 25 m-site.
In conclusion, opening a drainage ditch in cold waterlogged
paddy fields affects rice yield, soil nutrients, microbial
abundances and community structures.
