土壤微塑料污染无处不在,但不同土地利用类型中微塑料的垂直分布特征尚不清楚。在这项研究中,微塑料的丰度,颗粒大小,形状,颜色,和聚合物类型在0-20厘米,20-40厘米,和七个土地利用类型的40-60厘米土壤层(林地,草原,玉米,小麦,棉花,polytunnel,和温室)在寿光市进行了系统的调查,中国典型的农业城市。结果表明,寿光市三个土层从上到下的平均微塑性丰度分别为1948.1±992.5、1349.4±654和670.1±341.6kg-1。在表层土层(0-20厘米),设施土壤中微塑料的丰度明显高于其他土地利用类型。在农业土壤中,微塑料主要是小尺寸(<0.5毫米),电影和片段,PE和PP。7种土地利用类型的深层土壤(40-60厘米)的平均微塑性丰度为349.1±62.8(林地),284.9±113.9(草地),657.1±127.1(玉米),537.8±137.4(小麦),851.4±204.2(棉),878.5±295.7(多隧道),1132.2±304.5(温室)项目分别为kg-1,在所有三个土层中占11%至19%。在深层土壤(40-60厘米)中,小尺寸和颗粒状微塑料的百分比增加。相关分析表明,土壤环境因子(pH,EC,总磷,总氮,和有机碳)对分布的影响不同程度,碎片化,和微塑料的运输。这项研究的结果有助于更好地了解农业和非农业土壤中土壤微塑料的污染和垂直分布,以及为制定预防和管理政策提供重要数据。
Soil microplastic pollution is ubiquitous, but the vertical distribution characteristics of microplastics in different land use types are unclear. In this study, the microplastic abundance, particle size, shape, color, and polymer type in 0-20 cm, 20-40 cm, and 40-60 cm soil layers of seven land use types (woodland, grassland, maize, wheat, cotton, polytunnel, and greenhouse) were systematically investigated in Shouguang City, a typical agricultural city in China. The results showed that the average microplastic abundance from top to deep for the three soil layers of Shouguang City were 1948.1 ± 992.5, 1349.4 ± 654, and 670.1 ± 341.6 items kg-1. In the top soil layer (0-20 cm), the abundance of microplastics in facility soils was significantly higher than in other land use types. In agricultural soils, microplastics were predominantly small size (<0.5 mm), films and fragments, PE and PP. The average microplastic abundance in deep soils (40-60 cm) of the seven land use types was 349.1 ± 62.8 (woodland), 284.9 ± 113.9 (grassland), 657.1 ± 127.1 (maize), 537.8 ± 137.4 (wheat), 851.4 ± 204.2 (cotton), 878.5 ± 295.7 (polytunnel), 1132.2 ± 304.5 (greenhouse) items kg-1, respectively, accounting for 11 % to 19 % in all three soil layers. The percentage of small size and pellet microplastics increased in deep soils (40-60 cm). Correlation analysis showed that soil environmental factors (pH, EC, total phosphorus, total nitrogen, and organic carbon) influenced to different extents the distribution, fragmentation, and transport of microplastics. The results of this study contribute to a better understanding of contamination and vertical distribution of soil microplastics in agricultural and non-agricultural soils, as well as provide important data for the development of preventive and management policies.