Nanoplastics in agriculture: leveraging twenty years of engineered nanomaterials research

Abstract

Nanoplastics (NPs) are emerging contaminants in agriculture. Although the relative study is still limited, it can build on two decades of research on engineered nanomaterials (ENMs). ENMs provide methods, models, and mechanistic insights that help frame NP research, while NPs present unique challenges due to their polymer diversity, weathering, and role as carriers of additives and pollutants. First, characterization requires hybrid methods. ENM-based tools remain useful, but NPs also demand polymer-focused approaches to capture their heterogeneity from weathering, additives, and surface aging. Second, plant interactions may occur via roots, seeds, and leaves. Unlike ENMs that release reactive ions, NPs rely on size, hydrophobicity, and surface groups, raising concerns about membrane disruption and potential transgenerational transport. Third, soil acts as a dynamic sink where NPs differ from dissolving ENMs by undergoing physical aging and heteroaggregation, while serving as a vector that enhances or inhibits agrochemical mobility. Fourth, microbial responses are shaped less by direct toxicity and more by NP-specific features that alter nutrient cycling and resistance gene dynamics. By comparing ENMs and NPs, future research can accelerate mechanistic understanding and build predictive models. Clarifying NP behavior in agriculture is essential for soil health, crop productivity, and food security.