Long-term evolution of soil quality in citrus orchard terrace system: A whole life cycle perspective.

Terracing is widely recognized as an effective strategy for mitigating soil erosion and preserving soil quality. This study aimed to evaluate the variations in soil aggregate C, N, and P composition, as well as the soil quality index (SQI), in subtropical citrus orchards of different plantation ages (PA) and across various terrace positions (TP). Surface soil samples (0-20 cm) were collected from four TP categories: terrace wall (TW), slub ditch (SD), under grove (UG), and between grove (BG), across varying PA (5, 15, 25, 35, and 45 years).