Microplastics are widespread contaminants in soils and terrestrial ecosystems in many areas worldwide. In this study, we measured soil organic carbon (SOC) and soil organic matter (SOM) in microplastic-treated soils to determine if the presence of microplastics could affect the accuracy of carbon-based soil quality indicator measurements. Six different sizes and types of microplastics were selected, and six soil samples were used to evaluate the impacts. Treating soil with polyethylene and low-density polyethylene significantly increased SOC (p < 0.05) when measured with the modified Walkley & Black method; microplastic addition (0.01%, v/v) increased SOC by >40% compared to control organic carbon-poor soil (<10.0 g kg⁻¹). We conclude that the microplastics can disrupt the accurate measurement of SOC. Likely, the physicochemical treatment used in the SOC measurement process can cause the organic compounds and/or carbon complexes to be extracted from microplastics, and this can affect the results. Considering that SOC is a main indicator for assessing soil quality and the global carbon cycle, overestimations caused by microplastic contamination should be further discussed to identify appropriate ways to deal with microplastics as a new carbon source in the environment.

在全球许多地区，微塑料是土壤和陆地生态系统中广泛的污染物。在这项研究中，我们测量了经过微塑性处理的土壤中的土壤有机碳（SOC）和土壤有机质（SOM），以确定微塑料的存在是否会影响碳基土壤质量指标测量的准确性。选择了六种不同尺寸和类型的微塑料，并使用六种土壤样品评估了影响。 用改良的Walkley＆Black方法进行测量时，用聚乙烯和低密度聚乙烯处理土壤可显着提高SOC（p <0.05）。与对照的有机碳贫瘠土壤（<10.0 g kg ^-1）相比，微塑料添加（0.01％，v / v）使SOC增加> 40％）。我们得出的结论是，微塑料可能会破坏SOC的准确测量。SOC测量过程中使用的物理化学处理可能会导致有机化合物和/或碳络合物从微塑料中提取出来，这可能会影响结果。考虑到有机碳是评估土壤质量和全球碳循环的主要指标，应进一步讨论由微塑料污染引起的高估，以找出适当的方法将微塑料作为环境中的新碳源进行处理。