The karst region of Southwest China is characterized by shallow soil profiles and high hydraulic permeability. Driven by the combined influence of intensive agricultural activities and heavy precipitation, sloping farmland represents the primary source of sediment yield within this area. While previous studies have demonstrated that soil and water loss are inextricably linked to tillage practices, long-term experimental evidence derived from in situ monitoring remains scarce, leading to inconsistent findings regarding the efficacy of various tillage measures. This study presents a 10-year field investigation (2014-2023) utilizing 54 runoff plots (20 & times;5 m, slope gradients of 13-25 degrees) established across 16 sites in the karst region of Southwest China. We analyzed rainfall, runoff, and sediment yield data to evaluate the long-term conservation effects of four tillage practices: contour ridge (CR), longitudinal ridge tillage (LR), contour tillage (CT), and longitudinal tillage (LT). Bare land (BL) served as the control treatment. The results indicate that: (1) runoff and sediment yield events exhibited asynchrony across all tillage practices. The frequency of non-erosive runoff events (runoff without sediment yield) followed the order: CR > CT > LR > LT > BL. (2) The critical rainfall thresholds for initiating soil erosion varied significantly among tillage practices; CR (15.08 mm) and CT (14.76 mm) exhibited significantly higher thresholds compared to BL (12.73 mm). (3) Relative to BL, CR and CT significantly reduced runoff depth by 78.57% and 57.86%, and soil loss rates by 83.13% and 83.84%, respectively. The conservation efficacy of these practices was most pronounced during moderate to torrential rainfall events (10-100 mm) but attenuated during extreme rainfall events (>100 mm). (4) Rainfall was identified as the primary driver of runoff and soil loss, followed by vegetation coverage. In conclusion, CR and CT emerged as the most effective tillage practices for soil and water preservation in the researched area. These findings provide critical empirical evidence for optimizing land management strategies in karst regions.