Improvement of physico-chemical properties and microbiome in different salinity soils by incorporating Jerusalem artichoke residues

Soil salinization is becoming increasingly serious, threatening the development of ecological agriculture that aims at high yield, high efficiency and closed-loop cycles. In this study, residues of Jerusalem artichoke were incorporated in three soils differing in salinity, and the physical and chemical properties of soil and soil microbial community were characterized over time. After residue incorporation, the soil pH fluctuated between 6.8 and 8, trending toward neutrality; the soil salinity decreased significantly. The total nitrogen content increased significantly, whereas the soil organic matter content increased initially and then decreased. Soil microbiome abundance and diversity increased, with a significant increase in the population of moderate halophiles and cellulose-decomposing bacteria in soil. Compared with the genera adapted to medium-to-high salt concentration, the abundance and diversity of the low-salt genera were higher. The degradation rate of residues increased with time, with cellulose degradation being strongest, followed by hemicellulose, and finally lignin. In summary, incorporation of Jerusalem artichoke residues can improve soil physical and chemical properties and the microbial community structure, which provides a theoretical basis for improving saline-alkali soils, rational utilization of crop residues and promoting sustainable development of modern agriculture.