The influence of straw and earthworms on microorganisms in the salinized soil under vertical gradient

This study conducted a 90-day cultivation experiment to investigate the effect of the combined remediation facility using straw and earthworms on saline soil. All treatments resulted in the downward migration of salt. Among them, the SE group reduced the electrical conductivity of the surface soil from 2301.55 μS·cm−1 to 959.56 μS·cm−1. On the 90th day, the SE group increased the number of degrading bacteria of straw in the three layers of soil by 1.07−6.24 times compared to other treatment groups, and also increased the abundance of salt-sensitive bacteria in the surface soil. The earthworm's intestinal tract provided an enriched habitat for the degrading bacteria of straw, and the earthworm feces colonized the soil, which could optimize the salt distribution and microbial community structure of saline soil. This combined method is an effective approach for improving saline soil in the facility.