5. Conclusions
In this study, the modification effect of in situ Jerusalem
artichoke cultivation on the micro-ecological rhizosphere environment in
the saline-alkali soils along the southeast coast of China was
elucidated from a microbial perspective. The root system of Jerusalem
artichoke was distributed mainly in the soil layer 75-175 mm, avoiding
salt damage (high salinity in the top and the deeper layers). The root
channels of Jerusalem artichoke improved not only the physical structure
of saline soil, but also provided basic conditions for optimizing the
soil micro-ecological environment. Rhizosphere exudates (such as
carbohydrates, hydrocarbons, acids, etc.), produced by Jerusalem
artichoke and soil microbial community, could improve the habitat of
saline soil. The community diversity and richness of the autotrophic
bacteria and nitrogen-fixing bacteria were greater in the rhizosphere
than bulk soils. Many of identified microorganisms participate not only
in the carbon and nitrogen cycles, but also in the biogeochemical cycles
of other elements, promoting material cycling and energy flow in the
micro-ecological environments in saline soils. These findings provided a
scientific basis for understanding the biotransformation of carbon and
nitrogen in saline soil and the positive effects of Jerusalem artichoke
on the micro-ecological rhizosphere environment in saline soil.