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.