Organic fertilizers as a vector of microplastics: A comprehensive review of sources, dispersion, and environmental consequences

Microplastics (MPs) are frequently reported in agricultural soils due to the application of organic fertilizers originating from land-based sources. These MPs are formed through the degradation of plastics, personal care products, synthetic textiles, and the utilization of sewage sludge in farming. This review presents the research findings on the sources of MPs in organic fertilizers and their dispersion behavior and consequences. MPs affect the stability and structure of the soil as well as the cycling of nutrients and microbial activities within the soil. There is also clear evidence of the potential impacts of MPs on plant health and the risk of these particles entering the food chain and affecting other ecosystems. Organic fertilizers contaminated with MPs threaten soil health and food safety. This review focuses on their sources, impacts on plant growth, and the necessity for better research methods. Also elucidate dispersion pathways through direct soil incorporation, mulching, and fertigation. A future study should aim to determine the effects and formulate strategies to mitigate the impacts of MP contamination on agricultural ecosystems. Moreover, this study further reviews recent efforts to understand MP contamination of organic fertilizers and recommends future research. The paper points out the need for better data analyses and interdisciplinary efforts to appropriately minimize the environmental impact of MPs. Addressing MPs contamination in organic fertilizers requires interdisciplinary collaboration and evidence-based policy frameworks to ensure agricultural sustainability and food security. Future agricultural practice can be supported through research exploring sources, pathways, and risks of MPs in the agricultural context to lead to global environmental health. • Microplastics in organic fertilizers threaten soil health and food safety. • Microplastics impact soil structure, nutrient cycling, and microbial activities. • Contaminated fertilizers pose risks to plant health and food chain safety. • Better research methods needed to mitigate MPs in agricultural ecosystems. • Interdisciplinary efforts required for sustainable, MP-free agricultural practices.