Elaeagnus angustifolia can improve salt-alkali soil and the health level of soil: Emphasizing the driving role of core microbial communities

Abstract

Saline-alkali environments are widely distributed in China and significantly hinder the development of agriculture. This study characterizes the long-term effects of planting Elaeagnus angustifolia (E. angustifolia) on the physical and chemical properties, enzyme activities and microbial community characteristics of saline-alkali soil in the Songnen Plain (1, 2 and 3 years). The results showed that planting E. angustifolia reduced soil pH and electrical conductivity (EC) and increased soil total phosphorus (TP), total nitrogen (TN), nitrate nitrogen (Nni), total potassium (TK), dissolved organic C (DOC), dissolved organic matter (DOM) and available potassium (AK) content and catalase, urease, polyphenol oxidase, phosphatase, sucrase and cellulase enzyme activities, and the results peaked in the 3 year. High-throughput sequencing showed that the bacterial abundance and diversity were as follows (from high to low) y3 > y2 > y1 > CK. E. angustifolia resulted in an increase in the relative abundance of the dominant bacteria. Proteobacteria and Pseudomonas were the major phylum and genus, respectively. Redundancy analysis showed that changes in the soil microbial community significantly affect the physical and chemical properties of the soil, with Proteobacteria members being the key microorganisms that reduce soil salinity. Network analysis showed that Pseudomonas (Proteobacteria) participated in the synthesis of key soil enzymes. 16S rRNA sequencing predicted that the expression of genes related to carbon (rbcL, acsA, acsB, Pcc and accA) and nitrogen (amoA/B, nxrA, hao, gdh, ureC and nosZ) transformation increased, and Pseudomonas members were key regulators of carbon and nitrogen dynamics. In conclusion, the planting of E. angustifolia could improve the physical and chemical properties of the soil by releasing root exudates into the soil and increasing the diversity and richness of soil microbial communities to improve saline-alkali soil, providing a theoretical basis for improving saline-alkali soil and promoting the sustainable development of modern agriculture.

Keywords: Elaeagnus angustifolia; Enzyme activity; Saline-alkali soil; Soil bacterial community structure; Soil physical and chemical properties.