LDPE and biodegradable PLA-PBAT plastics differentially affect plant-soil nitrogen partitioning and dynamics in a Hordeum vulgare mesocosm.
LDPE and biodegradable PLA-PBAT plastics differentially affect plant-soil nitrogen partitioning and dynamics in a Hordeum vulgare mesocosm.
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DOI：
10.1016/j.jhazmat.2023.130825
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发表时间：
2023-01
影响因子：
13.6
通讯作者：
M. Reay;Lucy M. Greenfield;Martine Graf;C. Lloyd;R. Evershed;D. Chadwick;Davey L. Jones
中科院分区：
文献类型：
--
作者：
M. Reay;Lucy M. Greenfield;Martine Graf;C. Lloyd;R. Evershed;D. Chadwick;Davey L. Jones
微型和大型塑料是农业环境中新出现的污染物，但它们对植物-土壤-微生物系统中氮素循环和分配的影响却知之甚少。在这项中尺度研究中，春大麦(Hordeum uggarL.)暴露在由低密度聚乙烯(LDPE)或可生物降解塑料制成的宏塑料或微型塑料中，其浓度相当于使用地膜1年、10年和20年。将15N标记的肥料分配到植物生物量、土壤和渗滤液中，产生了部分质量平衡。通过对土壤微生物蛋白质的15N稳定同位素分析，探讨了土壤氮的分配。随着LDPE微塑料淋洗氮的增加，植物对15N的吸收随浓度的增加而下降。可生物降解塑料对土壤微生物蛋白质的同化作用较高，这与可生物降解塑料的早期降解有关。15N在土壤无机N库中的分配受LDPE大小的影响，对微生物蛋白库的同化程度较低。虽然微塑料和大塑料改变了土壤氮素循环，但对植物健康的有限影响表明，在与农业相关的浓度下，没有达到负面影响的阈值。这项研究强调了传统塑料和生物降解塑料的区别，并强调在未来的研究中必须考虑微型和大型塑料对土壤氮素循环的相互作用。
Micro and macroplastics are emerging contaminants in agricultural settings, yet their impact on nitrogen (N) cycling and partitioning in plant-soil-microbial systems is poorly understood. In this mesocosm-scale study, spring barley (Hordeum vulgareL.) was exposed to macro or microplastic produced from low density polyethylene (LDPE) or biodegradable plastic at concentrations equivalent to 1, 10 and 20 years of plastic mulch film use. Partitioning of15N-labelled fertiliser into plant biomass, soil and leachate yielded a partial mass balance. Soil N partitioning was probed via compound-specific15N-stable isotope analyses of soil microbial protein. Concentration-dependent decreases in plant15N uptake occurred with increased leached nitrogen for LDPE microplastic. Assimilation into soil microbial protein was higher for biodegradable plastics, which we associate with early-stage biodegradable plastic degradation. Partitioning of15N into inorganic soil N pools was affected by LDPE size, with lower assimilation into the microbial protein pool. While microplastics and macroplastics altered soil N cycling, the limited impacts on plant health indicated the threshold for negative effects was not reached at agriculturally relevant concentrations. This study highlights the difference between conventional and biodegradable plastics, and emphasises that the interplay of micro and macroplastics on soil N cycling must be considered in future studies.