Maize–potato intercropping enhances aggregate stability and AMF diversity in red soils of Southern China

Enhancing soil aggregate stability is fundamental to sustaining ecosystem services and mitigating land degradation. However, the mechanisms governing stabilization, specifically the mediatory role of arbuscular mycorrhizal fungi (AMF) in maize ( Zea mays L.)–potato ( Solanum tuberosum L.) intercropping, remain largely uncharacterized. A 5‐year field experiment was conducted to systematically analyze the changes in physicochemical properties, glomalin‐related soil proteins, enzymatic activities, and aggregate stability of non‐rhizosphere soil under different cropping patterns (monoculture and intercropping) and different growth stages (T1, jointing/seedling; T2, tasseling/peak flowering; T3, maturity). Additionally, the AMF community characteristics in rhizosphere and non‐rhizosphere soils were analyzed at the T2 stage. Results showed that the vigorous vegetative growth stage (T2) of both maize and potato exhibited peak extracellular enzyme activities, total glomalin‐related soil protein (T‐GRSP) accumulation, and aggregate stability. Compared with monoculture, maize–potato intercropping significantly enhanced rhizosphere soil urease, invertase, and catalase activities, as well as non‐rhizosphere soil organic matter and easily extractable glomalin‐related soil protein contents at the T2 stage, while concurrently increasing the proportion of >2.0 mm aggregates and mean weight diameter in non‐rhizosphere soil by 10.98%–88.84%. At this stage, potato intercropping increased AMF community diversity while concurrently elevating the relative abundances of Unclassified_f__Gigasporaceae , Scutellospora , and Gigaspora . Furthermore, AMF indirectly enhanced soil aggregate stability via the positive regulation of T‐GRSP. This study clarifies biophysicochemical pathways of crop diversity enhancing soil structural stability, supporting sustainable cropping management and erosion control in diverse cropping systems.