Abstract:

To clarify the regulatory effects and key driving factors of different mulching practices on rhizosphere microecology in wolfberry, 10-year-old ‘Ningqi No. 1’ plants were used as the experimental material, and 4 treatments were established: straw mulching (SM), horticultural ground fabric mulching (CM), black plastic film mulching (BM), and grass cover (CK). Soil physicochemical properties, enzyme activities, microbial biomass carbon and nitrogen, microbial abundance, and community structure were determined, followed by correlation analysis, redundancy analysis, and principal component analysis. The results showed that all mulching practices improved the rhizosphere soil environment to varying degrees, with SM showing the strongest effect. Compared with CK, SM increased soil organic matter and moisture by 23.23% and 22.85%, respectively, and decreased pH and soil temperature by 9.51% and 8.32%, respectively. The activities of urease, sucrase, alkaline phosphatase, and catalase were increased by 52.67%-59.84%. Microbial biomass carbon, microbial biomass nitrogen, bacterial abundance, fungal abundance, and total microbial abundance increased by 30.39%, 41.25%, 30.88%, 132.26%, and 32.61%, respectively. SM also increased fungal community richness and diversity and promoted the enrichment of functional taxa. CM and BM showed certain positive effects, but their overall effects were weaker than that of SM. The comprehensive evaluation based on principal component analysis followed the order of SM>CM>BM>CK. In short, straw mulching can more effectively coordinate soil nutrients, moisture and temperature conditions, enzyme activities, and microbial community structure, and can serve as a suitable mulching practice for rhizosphere micro-ecology regulation in wolfberry orchards in arid regions of northwestern China.

Key words: Lycium barbarum L., mulching practice, rhizosphere microbial communities, soil enzyme activity, micro-ecology regulation