Microplastic contamination in agricultural systems: impacts on plant productivity, economic losses, and supply chain resilience

Abstract

Microplastics (MPs) have transitioned from a predominantly marine concern to a defining threat facing terrestrial agroecosystems, where croplands now function as one of the largest global reservoirs of plastic particles. This review synthesizes evidence to construct an integrated narrative that links the entry of MPs into farmland with declining plant productivity, quantifiable economic losses, and the erosion of agricultural supply chain resilience. The synthesis is based on a documented search of Web of Science, Scopus, ScienceDirect and Google Scholar covering January 2018 to March 2026, with explicit inclusion and exclusion criteria reported in Section 1.1. Sources, fate and soil-phase processes are treated in condensed form, because they are already covered comprehensively elsewhere; we retain only the evidence that propagates into crop, economic and supply-chain outcomes. Building on these soil-level disturbances, we evaluate the phytotoxic consequences for crops, spanning inhibited germination, impaired root architecture, reduced photosynthetic efficiency, disrupted nutrient acquisition, and the uptake and translocation of nano-sized particles into edible tissues. A central contribution of this review is the explicit coupling of these biophysical impacts to their economic and systemic dimensions, because recent global meta-analyses estimate that MP-induced photosynthetic suppression alone may reduce staple crop production by tens to hundreds of millions of tons annually, translating into substantial revenue losses, quality downgrading, remediation expenditure, and heightened exposure of food supply chains to shocks. Rather than reporting these modelled outputs at face value, we dissect the inferential chain that produces them, from effect size to biomass to harvestable yield to price, and we identify the assumptions at each step that determine whether the resulting figures are decision-grade. We complement the global estimates with farm-level cost–benefit evidence showing that the private returns to plasticulture remain positive while the contamination externality contributes under one percent of the accounted benefits of current management, which explains the persistence of practices that degrade the productive base. Throughout, illustrative case studies from China, Chile, Australia, and Europe are embedded within each thematic section rather than treated in isolation, demonstrating how local contamination patterns propagate into landscape- and market-scale consequences. We further appraise mitigation and remediation options, ranging from source reduction and material substitution to biochar amendment, and we assess emerging governance instruments such as the FAO Voluntary Code of Conduct and circular-economy regulation. Finally, we identify persistent knowledge gaps concerning the calibration of field-realistic dose–response relationships, the construction of decision-grade economic estimates, and the severe geographical imbalance of the evidence base, in which South Asia, sub-Saharan Africa and Latin America are collectively represented by a small fraction of published field studies, and we outline research priorities to safeguard soil health and food security. The review argues that microplastic contamination should be reframed not merely as an ecotoxicological problem but as a slow-onset stressor with strategic implications for the stability of global food systems.