Crop diversity promote the recovery of fungal communities in saline areas of the Western Songnen Plain

Phytoremediation has been shown to be an effective strategy for saline land restoration, and the establishment of appropriate vegetation planting systems for saline reclamation requires research into specific areas affected by salt. Cropping types for saline phytoremediation have not been well documented for soil microbial recovery in the Western Songnen Plain. In this study, we aimed to investigate the effects of rRotation and mixtures cropping types on soil microbes in saline areas of the Western Songnen Plain and to compare them with monoculture areas used as controls to assess variability between cropping types. The fungal communities of the soils of the different cropping types were assessed by Illumina Miseq sequencing. The results showed that cropping types and soil depths had a significant effect on OTU richness. PcoA analysis showed significant differences in fungal community structure in soil samples from three cropping types with two depths. In addition, Mantel test identified TN, TP, and AK as the main environmental factor associated with fungal community structure. The dominant fungal community genera Leptosphaerulina, Alternaria, Myrothecium, Gibberella and Tetracladium were associated with different soil properties and there were significant differences in the genera between the different cropping types. Null-model analysis revealed that the fungal community assembly of the mixtures in 0-15cm soil depth was dominated by determinism unlike the other two cropping types. Furthermore, fungal symbiotic networks were more complex in rotation and mixtures than in monoculture soils, reflected in more nodes, more module hub and connector. FUNGuild analysis showed that cropping types changed the nutritional patterns of fungi. Overall, mixtures is the best option in restoring soil microorganisms in the saline areas of the Western Songnen Plain. These findings can provide some theoretical basis for further restoration of saline-alkali lands.