Data for "How does integrating multi-scale monitoring and compound-specific isotope analysis improve the evaluation of S-metolachlor degradation in agro-ecosystems?"

The persistence of pesticides in surface water threatens the quality of drinking water resources. A major challenge for water quality management is quantifying pesticide export, degradation, and persistence at the catchment scale. Compound-specific isotope analysis (CSIA) may help to evaluate the contribution of pesticide biodegradation in topsoil and water, as it is generally unaffected by non-degradative processes such as dilution, sorption, and volatilization. here we provide a datatset compagnion of a study using multi-scale monitoring where CSIA was combined with a mass balance approach to determine the source apportionment and degradation contribution to the overall dissipation of S-metolachlor, a widely used herbicide, in the Souffel catchment (115 km²) during a corn and sugar beet growing season. We anticipate that CSIA will enhance surface water management by improving the diagnosis of pesticide off-site transport and degradation. This approach can support the development of efficient regulatory strategies aimed at preserving and restoring aquatic ecosystems.