Mulching influences pear yield and quality by changing rhizosphere microbial community structure in the arid region of Northwest China

Hongxu Li¹Peigen Li²Gang Cao¹Mingxin Zhao¹Zhiyi Zhu²Yanwei Ma²Wei Wang¹Sufang Cao¹Yangchun Xu²Caixia Dong^2*

• ¹CAAS Gansu Academy of Agricultural Sciences, Lanzhou, China
• ²Nanjing Agricultural University, Nanjing, China

This study examined the impact of two mulching methods on soil temperature, moisture, rhizosphere microbes, and the yield and quality of pears in a pear orchard located in the arid region of Northwest China. The treatments applied to the soil surface included no mulching (CK), plastic film mulching (FM), and straw mulching (SM). Rhizosphere soil samples were collected prior to pear harvest to analyze soil physicochemical properties. Additionally, soil microbial community characteristics were assessed using high-throughput sequencing (16S rRNA and ITS). The results indicated that both FM and SM significantly improved pear yield and quality compared to CK. Principal coordinate analysis and permutational multivariate analysis of variance demonstrated that the soil microbial community structure was significantly altered by FM and SM. Proteobacteria and Acidobacteria emerged as the dominant bacterial phyla, while Ascomycota was the predominant fungal phylum in the rhizosphere soil. The FM treatment significantly increased the abundance of Gram-negative bacteria while reducing the presence of Gram-positive bacteria. Network analysis revealed that mulching significantly affected the ecological network of rhizospheric bacteria and the distribution of indicator species. Specifically, the ecological module formed under the FM treatment exhibited increased abundances of indicator species positively correlated with pear yield and quality. Soil moisture content, organic matter, and microbial ecological modules had strong positive influences on pear yield and sugar/acid ratio, highlighting that mulching affects pear yield and quality by modifying soil physicochemical properties and rhizosphere microbes. Compared to the SM treatment, FM further enhanced pear yield and quality in the arid region of Northwest China by improving soil nutrient content, soil moisture, and microbial community structure, including the recruitment of functional microbes.