Abstract:

This study explored the structural variations and diversity of soil rhizosphere microbial communities in dryland loam walnut orchards, aiming to establish a theoretical basis for improving high-quality walnut production. The research was conducted at the walnut experimental orchard of the Pomology Institute, Shanxi Agricultural University, through long-term positioning experiments utilizing various fertilization regimes. High-throughput sequencing of the 16S rRNA gene, along with one-way ANOVA, was employed to assess the community structures of soil rhizosphere bacteria and fungi under different fertilization treatments, including CK (no fertilization with natural grass cover), MG (sheep manure with artificial grass cover), and M (sheep manure with natural grass cover). The results revealed that organic fertilizer application significantly enhanced soil nutrient content, with the combination of sheep manure and natural grass cover exhibiting the most substantial effect. Furthermore, the application of organic fertilizers significantly improved soil enzyme activity, particularly when sheep manure was combined with artificial grass cover, thereby effectively accelerating soil nutrient cycling. Moreover, the integration of organic fertilization with grass cover had been shown to enhance bacterial and fungal populations and community structures, thereby increasing the abundance of microorganisms involved in nitrogen and carbon cycles and facilitating nutrient cycling and transformation. In the context of dryland conditions in Shanxi, the promotion of organic fertilization and inter-row grass cover in loam walnut orchards could significantly improve the structure and diversity of soil microbial communities, enhance soil nutrient availability, and optimize soil ecological conditions.

Key words: different fertilization patterns, rhizosphere soil, microorganisms, biological communities and diversity, walnut orchard