School of Resources and Environment, Henan Institute of Science and Technology, 90 Eastern Hualan Avenue, Xinxiang, 453003, China.
Sci Rep. 2024 Nov 16;14(1):28328. doi: 10.1038/s41598-024-80124-8.
Microplastics (MPs)-induced changes in soil nutrient cycling and microbial activity may pose a potential risk to soil ecosystem. Although some studies have explored these topics, there is still a large space for exploration and a relative lack of research on the mechanism by which soil health and its functions are affected by these changes. Thus, this study investigated the effects of polyethylene (PE) MPs with two particle sizes (13 μm and 130 μm) at five concentrations (0%, 1%, 3%, 6% and 10%, w/w) on soil biochemical properties and ecosystem function. The findings revealed that the exposure to 13 μm MPs significantly reduced soil respiration (Res) rate, β-glucosidase (Glu) and catalase (CAT) activity, which accompanied with enhanced urease activity and decreased soil pH, available phosphorus (AP), dissolved reactive phosphorus (DRP), dissolved organic carbon (DOC) and available potassium (AK) content in most cases. However, 130 μm MPs exerted negligible influence on the DOC and DRP content, Glu and CAT activity. High concentrations of 130 μm MPs significantly reduced soil pH, total dissolved nitrogen (TDN), AP and AK content, but significantly increased soil Res rate. Overall, soil ecosystem function was significantly reduced by the addition of MPs. The Res rate, soil AP and DRP content and Glu activity were the most important predictors of soil ecosystem function. We found that the risk posed by MPs to soil ecosystem function was dose-dependent and size-dependent. These findings underscore that MPs can alter soil functions related to soil nutrient cycling and provide further insights into MPs behavior in agroecosystems.
微塑料（MPs）诱导的土壤养分循环和微生物活性变化可能对土壤生态系统构成潜在风险。尽管一些研究已经探讨了这些主题，但对于土壤健康及其功能受到这些变化影响的机制，仍有很大的探索空间和相对缺乏研究。因此，本研究调查了两种粒径（13μm 和 130μm）的聚乙烯（PE）MPs 在五个浓度（0%、1%、3%、6%和 10%，w/w）下对土壤生化特性和生态系统功能的影响。研究结果表明，暴露于 13μm MPs 显著降低了土壤呼吸（Res）速率、β-葡萄糖苷酶（Glu）和过氧化氢酶（CAT）活性，同时伴随着脲酶活性的增强和土壤 pH 值、有效磷（AP）、溶解态磷（DRP）、溶解有机碳（DOC）和有效钾（AK）含量的降低。然而，130μm MPs 对 DOC 和 DRP 含量、Glu 和 CAT 活性几乎没有影响。高浓度的 130μm MPs 显著降低了土壤 pH 值、总溶解氮（TDN）、AP 和 AK 含量，但显著增加了土壤 Res 速率。总体而言，添加 MPs 显著降低了土壤生态系统功能。Res 速率、土壤 AP 和 DRP 含量以及 Glu 活性是土壤生态系统功能的最重要预测因子。我们发现，MPs 对土壤生态系统功能的风险是剂量和尺寸依赖性的。这些发现强调了 MPs 可以改变与土壤养分循环相关的土壤功能，并为 MPs 在农业生态系统中的行为提供了更深入的了解。
