College of Land Science and Technology, China Agricultural University, Beijing, 100193, China; Institute of Plant Nutrition, Resources and Environment, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Institute of Agro-Resources and Environment, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang, 050051, China.
Chemosphere. 2024 Sep;364:143235. doi: 10.1016/j.chemosphere.2024.143235. Epub 2024 Aug 31.
Microplastics negatively impact soil health and productivity. Organic fertilizers constitute significant contributors of microplastics in agricultural soils. Nevertheless, comprehensive data on the diversity of microplastics in long-term fertilized soils remain unavailable. In this study, we assessed the presence of microplastics in soils subjected to application of three different organic fertilizers (pig manure, chicken manure, and sludge composts) over 12 years, and evaluated the potential ecological risks posed by microplastic accumulation. The average microplastic abundance in soil was 368.88 ± 207.97 (range: 90-910) items/kg. Microplastic abundance differed among fertilization treatments, with substantial increases of 16.67%, 71.67%, and 61.43% upon low to high application of the three treatments, respectively. Overall, the microplastics predominantly comprised fibers (70.94%) and fragments (25.25%), of which a substantial proportion constituted light-colored microplastics (transparent and white). The size of microplastics was mainly concentrated in the 1-2 mm range (39.96%), with rayon, polypropylene, polyester, and polyethylene being identified as the major types. The risk assessment indices of the three treatments were 229.38, 257.64, and 175.89, respectively, and were all classified as level 4 (high risk). The microplastic diversity integrated index and principal component analysis revealed that microplastics were uniformly distributed throughout the 0-20 cm soil depth consequent to tillage activity. Together, these findings provide a comprehensive assessment of microplastic pollution in long-term fertilized soils and serve as a scientific basis for reducing microplastic contamination in agricultural soils.
微塑料对土壤健康和生产力有负面影响。有机肥料是农业土壤中微塑料的重要来源。然而，长期施肥土壤中微塑料多样性的综合数据仍然缺乏。在这项研究中，我们评估了在 12 年的时间里，三种不同的有机肥料（猪粪、鸡粪和污泥堆肥）在土壤中的应用对微塑料存在的影响，并评估了微塑料积累带来的潜在生态风险。土壤中微塑料的平均丰度为 368.88±207.97（范围：90-910）项/kg。微塑料丰度因施肥处理而异，三种处理的低、中、高用量分别显著增加了 16.67%、71.67%和 61.43%。总体而言，微塑料主要由纤维（70.94%）和碎片（25.25%）组成，其中相当一部分是浅色微塑料（透明和白色）。微塑料的大小主要集中在 1-2mm 范围内（39.96%），鉴定出的主要类型有粘胶纤维、聚丙烯、聚酯和聚乙烯。三种处理的风险评估指数分别为 229.38、257.64 和 175.89，均为 4 级（高风险）。微塑料多样性综合指数和主成分分析表明，由于耕作活动的影响，微塑料在 0-20cm 土壤深度内均匀分布。总之，这些发现为长期施肥土壤中的微塑料污染提供了全面评估，并为减少农业土壤中的微塑料污染提供了科学依据。
