Environmental Fate, Transformation, and Interactions of Agrochemicals and Micro-Nano Plastics in Agricultural Ecosystem

The extensive use of agrochemicals and plastic materials has led to the accumulation of persistent pollutants in agricultural soils, raising concerns about agroecosystems through posing potential risks to soil and environmental health. This review synthesizes recent knowledge on these pollutant sources, including their distribution, fate, transformation pathways, and detection methods, as well as their impacts on soil physicochemical properties, microbial populations, plants, and ecosystems. Existing findings indicate that agrochemicals and micro-nano plastics (MPs-NPs) can significantly impede the stability of soil aggregation, increase soil water holding capacity (WHC) and porosity, reduce bulk density and infiltration, alter soil structure, and affect soil pH, cation exchange capacity (CEC), electrical conductivity (EC), and nutrient retention capacity. Moreover, exposure to these pollutants alters soil microbial communities, enzymatic activity, nitrification and denitrification processes, and arbuscular mycorrhizal fungi (AMF), thereby affecting carbon pools and fluxes as well as nutrient cycling. However, the magnitude and direction of these effects are strongly influenced by soil type, pollutant class, concentration, and physicochemical properties. Furthermore, terrestrial and aquatic ecosystems are negatively affected due to the presence of such persistent pollutants by impairing their physiological processes. Despite these findings, mechanistic understanding remains limited due to a lack of long-term field investigation and proper detection methods, particularly regarding NPs. A comprehensive understanding of agrochemical and MP-NP interactions is essential for developing sustainable soil management strategies and agroecosystems. Future studies should address the development of standardized NP detection methods and the conducting of long-term field studies to elucidate MP-NP and agrochemical interactions, soil impacts, and crop uptake mechanisms.