海南儋州农用地土壤微塑料赋存含量与分布特征

Research on storage capacity and distribution characteristics of soil microplastics with Danzhou farmland,Hainan

为掌握海南农用地土壤微塑料赋存含量与分布特征,以农用地不同农业种植区的土壤微塑料为研究对象,采用现场监测和实验室分析相结合的研究方法,探究不同区域表层土壤和不同深度剖面土壤中微塑料丰度含量与分布特征。结果表明:农用地表层土壤微塑料丰度范围为200.00~3900.00个/kg,平均丰度为933.33±767.04个/kg;土壤微塑料的成分主要为聚乙烯,覆膜地块丰度明显高于未覆膜地块,且与地块作物种植方式存在较强关联性;整个表层土壤均以偏小粒径(0.5~2.0 mm)微塑料为主,覆膜地块以白色颗粒、黑色薄膜、蓝色薄膜、半透明纤维塑料居多,未覆膜地块则以半透明的纤维塑料占主导;此外,纵向剖面土壤微塑料数量和丰度均随土层深度增加呈明显下降趋势,尤其是黑色、蓝色农膜塑料(聚乙烯)下降明显,均存在显著负相关性(P<0.05),而小粒径(<0.5 mm,0.5~1.0 mm)微塑料丰度所占比例明显升高,呈小型化的变化趋势,微塑料更易向深层土壤迁移和转化。综上,与国内外农田区域相比,海南儋州农用地土壤微塑料丰度整体处于偏高水平。

To master storage capacity and distribution characteristics of soil microplastics with farmland.Research on soil microplastics in different agricultural planting areas of farmland:a combination of field monitoring and laboratory analysis.And explored the microplastics abundance and distribution of topsoil with different areas and profile soil with different depths.Results revealed that microplastics abundance of topsoil in farmland were ranged from 200.00 ind/kg to 3900.00 ind/kg,with the mean were 933.33±767.04 ind/kg.Components of soil microplastics were mainly dominated by polyethylene(PE),its abundance of film-covered land were significantly higher than non-film covered land,which was closely related to crop planting methods of land.And microplastics of the whole topsoil were mainly composed of size range of 0.5~2.0 mm,the majority of film-covered land were white particles,black film,blue film and translucent fiber plastics,while non-film covered land were dominated by translucent fiber plastics.Moreover,number and abundance of microplastics in vertical profile soil decreased significantly with depth of soil layers,especially black and blue film plastics(polyethylene)decreased significantly,with a significant negative correlation(P<0.05).Abundance proportion of microplastics with smaller particle sizes(<0.5 mm,0.5~1.0 mm)showed a noticeable increased,indicated a trend towards miniature sizes,and microplastics were more proned to migrate and transform into deeper layers of soil.In conclusion,microplastics abundance in Danzhou farmland of Hainan were generally at a higher level,when compared with domestic and foreign farmland.