Effects of Different Organic Fertilization Regimes on Soil Physicochemical Properties and Bacterial Community Assembly to Promote Greenhouse-Cultivated Aloe vera Growth

<title>Abstract</title> <p> Sustainable production of greenhouse-cultivated aloe largely depends on soil quality and rhizosphere microbial stability. Organic fertilization is widely applied to improve farmland soil environment, whereas the long-term effects of different organic fertilizer regimes on soil fertility, plant growth and rhizosphere bacterial community assembly remain poorly documented in intensive aloe cultivation systems. This four-year greenhouse trial was conducted to systematically investigate how different organic fertilization practices regulate soil physicochemical properties, aloe growth performance, and rhizosphere bacterial diversity. Four treatments were established, including earthworm manure (QY), aloe-specific organic fertilizer (LY), conventional organic fertilizer (PY), and non-fertilized control (CK). Plant growth traits, soil fertility parameters, and rhizosphere bacterial community composition and diversity were comprehensively determined and compared across treatments. Long-term application of organic fertilizer significantly improved soil nutrient conditions and <italic>Aloe vera</italic> biomass, with the QY treatment shows the significant improvement effect. Soil organic matter (SOM) content increased by 40.76% under QY treatment. Fertilization regimes significantly reshaped bacterial community structure and diversity. Strong positive correlations were detected between dominant bacterial species and key soil nutrients. SOM and AP were verified as the primary edaphic drivers governing phylum-level bacterial community variation. QY and LY organic fertilizer treatments increased microbial community heterogeneity, while PY and CK fertilization treatments maintained relatively stable microbial community structure. These results indicate that earthworm manure (QY treatment) shows greater potential in improving soil quality and maintaining microbial ecological stability, making it an ideal fertilization strategy for healthy and sustainable <italic>Aloe vera</italic> production. </p>