<p>Understanding the relationship between environmental persistence, residue occurrence in harvested commodities and regulatory residue limits is central to herbicide risk evaluation. This study presents an integrated assessment of herbicide behaviour by combining field-derived soil dissipation data, terminal residue observations and cross-jurisdictional comparisons of maximum residue limits (MRLs) within an intensive subtropical agroecosystem. Dissipation kinetics for major herbicides were compiled from field experiments and compared with international reference values to characterize persistence behaviour under regional conditions. Terminal residues in harvested commodities across cereal and non-cereal cropping systems were evaluated using validated chromatographic analyses. Regulatory thresholds were examined across major authorities using heat-map visualization, hierarchical clustering and a Regulatory Divergence Index to quantify cross-jurisdictional variability. Field-derived dissipation half-lives showed molecule-specific variability. However, residues in harvested commodities remained consistently below quantification limits under recommended agronomic use patterns. In contrast, regulatory MRLs exhibited substantial divergence across jurisdictions. Multivariate analyses revealed that regulatory thresholds form distinct magnitude-based groupings primarily shaped by jurisdiction-specific regulatory frameworks, including precautionary default limits and crop-group extrapolation practices. The combined evidence indicates that environmental persistence, observed residue occurrence and regulatory threshold determination represent analytically distinct dimensions within herbicide assessment systems. Recognizing this separation is important for interpreting herbicide behaviour across environmental and regulatory contexts and may also help explain trade-related challenges associated with differing international residue standards.</p>