This study quantified the impact of management practices on soil organic carbon (SOC) stock in Hylocereus spp. (dragon fruit) systems, contrasting alternative management (AM) using cover crops with conventional management (CM) of bare soil, in a subtropical environment prone to erosion. A total of 100 soil samples were collected from four depths (0–5, 5–10, 10–20, and 20–30 cm) across AM plots, CM plots, and an adjacent grassland (control) during the dry season of 2022. Statistical analysis revealed a significant difference (p < 0.05) in SOC stock between the systems, following the pattern: AM (47.01 t ha⁻¹) > Grassland (45.77 t ha⁻¹) > CM (30.60 t ha⁻¹). The AM system, characterized by cover crops and minimal tillage, stored 16.41 t ha⁻¹ more SOC on average than the conventional system. The CM system exhibited the lowest SOC concentration below the plant, likely due to intensive tillage and lack of cover. The implementation of cover crops and reduced tillage in dragon fruit production systems (AM) significantly enhances SOC storage, reaching levels comparable to natural grassland. These practices are important for developing sustainable dragon fruit farming, especially in high-erosion areas, serving as a powerful tool for climate change mitigation and soil health improvement.