Spatial distribution of microplastics in Mollisols of the farmland in Northeast China: the role of field management and plastic sources

Although microplastics (MPs) have been widely found in farmland soil, the influence of pollutant sources and farmland management on MPs migration and distribution is poorly understood. In this study, we investigated the distribution of MPs in the 0–30 cm soil layers of vegetable fields with long-term mulching and surrounded by complex pollution sources under three management methods (MMs) (MM1, high fertilization dose and moderate tillage frequency; MM2, moderate fertilization dose and high tillage frequency; MM3, low fertilization dose and low tillage frequency) in Mollisols of Northeast China. Geostatistics combined with classical statistics were used to clarify the distribution of MPs and their driving factors. The results indicated that the polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyethylene terephthalate (PET), polyether urethane (PEUR) and a mixture of “PE and PP” (PE:PP) were found in the 0–30 cm soil layer. The dominant sizes of PE-MPs and non-PE-MPs (NPE-MPs) were 1–5 mm and 0.05) with the abundance of MPs in the 0–30 cm soil layer, but were significantly correlated (p