Cultivation of Morchella sextelata in saline-alkali soils of Ningxia: Multi-dimensional impacts on soil physico-chemical properties, enzyme activities, microbial ecology and functional genes

Aims ( Morchella spp.), precious edible and medicinal fungi with important economic and scientific value, have always attracted the attention of scientific researchers at home and abroad, while successful large-scale cultivation in multiple provinces drives a northward expansion of production regions from the south. China’s northward expansion of morel mushrooms cultivation faces challenges from saline-alkali soils in arid regions. The purpose of this paper is to clarify the effects of Morchella cultivation on the saline-alkali soil of Ningxia, Northwest China. Methods In this study, A comparative analysis was performed on the physical and chemical properties of soil, microbial community structure and function, and the expression of enzymes related to nitrogen metabolism in saline-alkali soils under three treatments: (A) an unplanted control, (B) one year of Morchella cultivation, and (C) two years of Morchella cultivation. Results The results indicated that Morchella cultivation positively contributed to the amelioration of saline-alkali soil, evidenced by a significant reduction in pH, alongside remarkable enhancements in nutrient contents and enzyme activities. Results based on metagenomic sequencing also revealed that morel mushroom cultivation drives a functional remodeling of the soil microbial community. On the one hand, it enhances the overall metabolic activity of microorganisms by upregulating core metabolic pathways such as ABC transporters, and Morchella cultivation also positively promotes denitrification, nitrogen assimilation, and reutilization in soil nitrogen metabolism. On the other hand, it disrupts the microbial network responsible for phenolic acid degradation, manifested by an increased gene abundance of the synthesis key enzyme PAL, while the dominant microbial contributors to the degradation core enzyme P34O and its encoding genes pcaG / pcaH shift from the original state (dominated by genera such as Arthrobacter ) to a less efficient structure (dominated by Microvirga and Sphingomonas ), ultimately leading to phenolic acid accumulation and the risk of hindering sustainable continuous cropping. Conclusion This study highlights the extent of soil alterations induced by morel mushroom cultivation in saline-alkali environments and its underlying mechanisms.