Zhang Yan, Dou Ming, Hao Song-Ze, Li Ping, Zhou Yu-Ze, Liang Zhi-Jie
Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.
School of Water Conservancy and Transportation, Zhengzhou University, Zhengzhou 450001, China.
Huan Jing Ke Xue. 2025 Aug 8;46(8):5345-5359. doi: 10.13227/j.hjkx.202407139.
Microplastics, as a new type of pollutant, have significant effects on the soil ecological environment. In order to investigate the effects of polylactic acid microplastics （PLA-MPs） on the physical and chemical properties of wheat rhizosphere soil and its microbial community structure, three contents （0.1, 0.5, and 1 g·kg） and particle sizes （150, 1000, and 4000 μm） were set up for pot experiments. The results showed that the addition of PLA-MPs significantly increased the contents of ammonium nitrogen （NH）, nitrate nitrogen （NO）, total phosphorus （TP）, and organic matter （OM） in rhizosphere soil and decreased the content of total nitrogen （TN） and pH value. For example, TP increased 19.046% and 21.075% at medium contents （0.5 g·kg） and medium particle size （1 000 μm）, respectively. Compared with those of the control group （CK）, the richness and diversity of rhizosphere soil microorganisms were significantly decreased, and the decreases were greatest at high contents （1 g·kg） and high particle size （4 000 μm）, respectively. The addition of PLA-MPs significantly increased the relative abundance of Actinobacteriota and Proteobacteria, while decreasing the relative abundance of Firmicutes, Gemmatimonadota, Myxococcota, and Bdellovibrionota. For example, the relative abundance of Actinobacteriota increased by 5.554% and 6.456% at medium contents （0.5 g·kg） and low particle size （150 μm）, and the relative abundance of Firmicutes decreased by 2.721% and 3.727% at high contents （1 g·kg） and low particle size （150 μm）, respectively. Compared with CK, PLA-MPs with different contents and particle sizes significantly reduced the number of biomarkers, and the reduction of biomarkers under low content （0.1 g·kg） and medium particle size （1 000 μm） was the largest. A significant negative correlation was observed between pH and the dominant microorganisms at the phylum level and genus level of the microbial community and a significant positive correlation between NO and Bacillus, Firmicutes, and Gemmatimonadota at the < 0.001 level. The research results can provide certain data and theoretical basis for evaluating the effects of PLA-MPs on the soil microbial environment.
微塑料作为一种新型污染物，对土壤生态环境具有显著影响。为了探究聚乳酸微塑料（PLA - MPs）对小麦根际土壤理化性质及其微生物群落结构的影响，设置了三种含量（0.1、0.5和1 g·kg）以及三种粒径（150、1000和4000 μm）进行盆栽试验。结果表明，添加PLA - MPs显著增加了根际土壤中铵态氮（NH）、硝态氮（NO）、总磷（TP）和有机质（OM）的含量，降低了总氮（TN）含量和pH值。例如，在中等含量（0.5 g·kg）和中等粒径（1000 μm）条件下，TP分别增加了19.046%和21.075%。与对照组（CK）相比，根际土壤微生物的丰富度和多样性显著降低，且在高含量（1 g·kg）和大粒径（4000 μm）条件下降低幅度最大。添加PLA - MPs显著增加了放线菌门和变形菌门的相对丰度，同时降低了厚壁菌门、芽单胞菌门、粘球菌门和蛭弧菌门的相对丰度。例如，在中等含量（0.5 g·kg）和小粒径（150 μm）条件下，放线菌门的相对丰度分别增加了5.554%和6.456%，在高含量（1 g·kg）和小粒径（150 μm）条件下，厚壁菌门的相对丰度分别降低了2.721%和3.727%。与CK相比，不同含量和粒径的PLA - MPs显著减少了生物标志物的数量，在低含量（0.1 g·kg）和中等粒径（1000 μm）条件下生物标志物减少幅度最大。在pH与微生物群落门水平和属水平的优势微生物之间观察到显著负相关，在<0.001水平下，NO与芽孢杆菌属、厚壁菌门和芽单胞菌门之间存在显著正相关。研究结果可为评估PLA - MPs对土壤微生物环境的影响提供一定的数据和理论依据。
