Potential sources and occurrence of macro-plastics and microplastics pollution in farmland soils: A typical case of China

Plastic debris (including macro-plastics, microplastics (MPs), and nanoplastics), defined as an emerging contaminant, has been proven to significantly affect soil ecosystem functioning. Accordingly, there is an urgent need to robustly quantify the pollution situation and potential sources of plastics in soils. China as the leading producer and user of agricultural plastics is analyzed as a typical case study to highlight the current situation of farmland macro-plastics and MPs. Our study summarized information on the occurrence and abundance of macro-plastics and MPs in Chinese farmland soils for the first time based on 163 publications with 728 sample sites. The results showed that the average concentration of macro-plastics, and the abundance of MPs in Chinese farmlands were 103 kg ha−1 and 4537 items kg−1 (dry soil), respectively. In addition, this study synthesized the latest scientific evidence on sources of macro-plastics and MPs in farmland soils. Agricultural plastic films and organic wastes are the most reported sources, indicating that they contribute significantly to plastic debris in agricultural soils. Furthermore, the modeling methods for quantifying macro-plastics and MPs in soils and estimating the stock and flow of plastic materials within agricultural systems were also summarized.Keywords: Abundancefarmland soilsmacro-plasticsmicroplasticsquantitative methodsource apportionmentHANDLING EDITORS: Hyunjung Kim and Jörg Rinklebe Disclosure statementThe authors report there are no competing interests to declare.Additional informationFundingThis research was supported by the National Natural Science Foundation of China under Grant [number 42277097]; the UKRI Global Challenges Research Fund (GCRF) and the Natural Environment Research Council project, "Do agricultural microplastics undermine food security and sustainable development in less economically developed countries?" under Grant [NE/V005871/1]; the International Cooperation and Exchange of the National Natural Science Foundation of China under Grant [NSFC-UNEP: 32261143459], and the High-level Team Project of China Agricultural University.