Mulching is an agronomic practice that improves orchard soil and promotes root growth. To investigate the regulatory effects of different mulching materials on soil properties, microbial communities, and root function in apple orchards, eight treatments were established: clean tillage (CK), organic fertilizer mulching (OFM), chopped corn straw mulching (SM1), chopped and bundled corn straw mulching (SM2), intact corn stover mulching (SM3), composted apple branch mulching (BM), horticultural ground cover fabric mulching (FM), and weed mulching (WM). The results showed that OFM, BM, SM1, and SM3 exhibited effective cooling effects during summer. During the peak root-flush period, OFM, SM3, and BM significantly reduced soil bulk density, increased porosity, enhanced soil organic matter and available nutrient contents, and elevated the activities of soil sucrase, urease, and catalase. Moreover, these treatments promoted the accumulation of carbohydrates and the uptake of mineral nutrients in roots. OFM and SM3 significantly increased the Simpson index of both soil bacterial and fungal communities, while BM improved the beta diversity of bacterial and fungal communities. OFM, SM3, and BM can effectively improve soil physicochemical properties, optimize microbial community structure, and enhance root nutrient uptake. It is recommended as a mulching measure for soil in northern apple orchards. Among the eight treatments evaluated, OFM, SM3, and BM exhibited superior performance in improving soil physicochemical properties, promoting root function, and enhancing microbial community diversity. Therefore, the findings of this study provide an effective soil management strategy for apple orchards in the cold northern regions of China.

Soil drought has become a major factor limiting global crop yields. Due to the absence of a main root and root hairs, blueberries are highly sensitive to drought stress, making their cultivation challenging in arid and semi‐arid regions. This study investigated the effects of foliar spraying with melatonin at different concentrations (100, 200, 300, and 400 μmol/L) on the drought resistance of half‐highbush blueberry ‘Northland’ under mild (55–60%), moderate (35–40%), and severe (20–25%) soil moisture levels, with normal irrigation as the control (CK). Results showed that drought stress significantly affected the physiological and biochemical traits of blueberries. Melatonin pretreatment improved drought resistance by enhancing photosynthetic performance, promoting osmotic adjustment, and increasing antioxidant enzyme activity. The optimal concentration varied with drought severity: 200 μmol/L under mild and moderate stress, and 300 μmol/L under severe stress. Overall, appropriate melatonin application strengthened the physiological and biochemical responses of half‐highbush blueberry ‘Northland’, improving its adaptability to drought conditions. These findings provide a theoretical basis for the drought‐resilient cultivation of half‐highbush blueberries in cold and arid regions similar to the Changbai Mountain area.