Comparative analysis of pesticide degradation pathways and stereoselective behavior in agricultural soils

Abstract

Objectives: This study examines the degradation pathways of chiral pesticides in agricultural soils, with a focus on their stereoselective behavior and environmental fate. Specifically, it explores the degradation kinetics of the chiral herbicide profoxydim, evaluating how soil chemistry, microbial activity, and environmental conditions influence stereoisomer persistence. Additionally, the study assesses the impact of biochar amendments on pesticide degradation dynamics.   Theoretical Framework: The research builds upon established principles of pesticide fate and transport, integrating stereoselectivity as a key factor in environmental risk assessment. The role of biochar in modifying microbial degradation, adsorption capacity, and bioavailability is also considered within the broader context of sustainable soil management.   Method: Advanced analytical techniques, including QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction and HPLC-MS/MS (High-Performance Liquid Chromatography coupled with Tandem Mass Spectrometry), were employed to quantify stereoisomers and their degradation products. Comparative analyses were conducted on soil samples with and without biochar amendments to evaluate changes in degradation kinetics and stereoselective persistence.   Results and Discussion: Findings indicate that certain stereoisomers of profoxydim exhibit prolonged environmental persistence, leading to potential ecotoxicological concerns. Soil chemistry and microbial activity significantly influence degradation rates, with biochar demonstrating the ability to alter pesticide behavior by modifying microbial interactions and adsorption processes. The stereoselective nature of degradation underscores the need for refined risk assessment strategies that account for isomer-specific persistence.   Research Implications: This study highlights the necessity of incorporating stereoselective analysis in pesticide regulation and environmental risk assessments. The observed influence of biochar on pesticide degradation presents a potential strategy for mitigating the environmental risks associated with pesticide use.   Originality/Value: By integrating stereoselective degradation analysis with soil amendment strategies, this research advances current understanding of pesticide fate in agricultural soils. The findings offer a novel approach to improving pesticide management and promoting sustainable agricultural practices through targeted soil amendments