National-scale mapping of time-dependent apparent degradation rates of tetracycline and sulfonamide antibiotics in Chinese cropland soils under a spring fertilization scenario.

= 0.576), reflecting stronger soil-driven controls on tetracycline degradation. Spatial predictions reveal pronounced east-west gradients for tetracyclines, with slower degradation in western and northwestern China, whereas sulfonamides exhibit generally faster and more spatially uniform degradation with a reversed northwest-southeast contrast. Uncertainty analysis indicates more robust predictions for tetracyclines and higher uncertainty for sulfonamides. These results provide the first parallel national maps of time-dependent apparent degradation rates for major veterinary antibiotics in Chinese croplands, offering a quantitative basis for large-scale fate modeling and region-specific risk management.