Introduction: In arid regions, soil degradation and nutrient scarcity limit the productivity of Korla fragrant pear (Pyrus bretschneideri Rehd.). This study aimed to systematically evaluate how bacterial fertilizer and different green manures affect rhizosphere ecological functions and yield formation.Methods: A field experiment was conducted in a Korla pear orchard with six treatments: bacterial fertilizer (JF), two planting densities of sweet clover (CMX1, CMX2), two planting densities of oil sunflower (DK1, DK2), and a control (CK). Soil physicochemical properties, enzyme activities, root architecture, and yield were analyzed.Results: Both bacterial fertilizer and green manures significantly reduced soil pH and EC, improved nutrient content, and enhanced enzyme activity. Bacterial fertilizer was more effective in boosting enzyme activity, while sweet clover excelled in improving soil properties. Low-density green manures outperformed high-density ones. Root activity, vessel area, and yield were significantly increased by all amendments, with bacterial fertilizer showing the strongest effect. PLS-SEM analysis identified root activity as a key mediator linking soil improvements to yield gains.Discussion: These results highlight the critical role of root activity in translating soil amendments into yield benefits. Among all treatments, low-density sweet clover (CMX1) offers the most cost-effective and sustainable strategy for improving soil fertility and pear yield in arid orchards.

The experiment aimed to address the issue of excessive nitrogen fertilizer application, explore an optimal model for combining reduced nitrogen fertilizer with organic fertilizer (sheep manure), and investigate their relationships with soil properties and pear tree physiology while assessing impacts on Korla fragrant pear yield. During the period from 2021 to 2023, 10-12-year-old pear trees at Awati Farm in Korla were selected for the study. Six treatments were established: no fertilization (CK), no nitrogen fertilizer application (N₀), conventional fertilization (N), nitrogen fertilizer reduction treatment (N₂ with a 20% reduction in nitrogen compared to conventional fertilization), and two combined treatments of reduced nitrogen fertilizer with two application gradients of organic fertilizer (F₁ and F₂, applying 22500 kg·hm^− 2 and 33750 kg·hm^− 2 of sheep manure, respectively), denoted as N₂F₁ and N₂F₂. Results showed that reducing nitrogen fertilizer application effect on soil physical and chemical properties and nutrient content, inhibited enzyme and root activities, increased root cortex thickness, and reduced the proportion of cellulose cell wall cells in phloem and xylem, as well as the total area of pear root vessels and slice area in the 20–40 cm soil layer. However, combining sheep manure improved these effects. Compared to full nitrogen application, N₂F₁ treatment significantly increased alkali-hydrolyzable nitrogen content in the 0–60 cm soil layer, soil organic matter in the 0–20 cm layer, total nitrogen in the 20–40 cm layer, protease activity in the 20–40 cm layer, and the number and proportion of phloem cellulose cell wall cells, while maintaining catalase and urease activities at levels similar to full nitrogen application. The N₂F₂ treatment significantly increased total nitrogen in the 0–20 cm soil layer, organic matter in the 40–60 cm layer, protease activity, root cortex thickness, and conduit and slice areas, with no significant change in root activity and total yield compared to full nitrogen application.

The sustainability of Korla fragrant pear orchards has been increasingly threatened by prolonged intensive agricultural practices. In response, biofertilizers and green manures have gained attention due to their potential to enhance soil structure, activate microbial functions, and improve nutrient uptake. However, the dynamic changes in soil bacterial communities under such interventions remain inadequately understood. This study was conducted from 2022 to 2023 in 7- to 8-year-old Korla fragrant pear orchards in Bayin’guoleng Mongol Autonomous Prefecture, Xinjiang. The treatments included: conventional fertilization (CK), biofertilizer (JF), oil sunflowers (DK1) with 25 cm row spacing and a seeding rate of 27 kg·hm⁻², oil sunflowers (DK2) with 25 cm row spacing and a seeding rate of 33 kg·hm⁻², sweet clover (CM1) with 20 cm row spacing and a seeding rate of 21 kg·hm⁻², and sweet clover (CM2) with 20 cm row spacing and a seeding rate of 27 kg·hm⁻². During the 2023 pear season, soil samples from the 0–20 cm layer were collected at the fruit setting, expansion, and maturity stages. Their physical and chemical properties were analyzed, and the structure and diversity of the soil bacterial community were examined using 16S rRNA gene high-throughput sequencing. Fruit yield was assessed at the maturity stage. Compared to CK, the relative abundance of Actinobacteria increased by 101.00%, 38.99%, and 50.38% in the JF, DK2, and CM1 treatments, respectively. DK1 and CM1 treatments resulted in a 152.28% and 145.70% increase in the relative abundance of the taxon Subgroup_7, while JF and DK2 treatments enhanced the relative abundance of the taxon Gitt-GS-136 by 318.91% and 324.04%, respectively. The Chao1 index for CM2 was 18.76% higher than CK. LEfSe analysis showed that the DK2 and CM2 treatments had a more significant regulatory effect on bacterial community structure. All treatments led to higher fruit numbers and yield compared to CK, with JF showing the largest yield increase. Fertilizer type, soil nutrients, and bacterial community structure all significantly positively influenced pear yield. In conclusion, high-density oil sunflower planting is the most effective approach for maintaining soil microbial community stability, followed by low-density sweet clover. This study provides a systematic evaluation of the dynamic effects of bio-fertilizers and different green manure planting patterns on soil microbial communities in Korla fragrant pear orchards, presenting practical, microbe-based strategies for sustainable orchard management.