聚乙烯微塑料浓度对黑土团聚体特征及其稳定性的影响  

Effect of Polyethylene Microplastic Concentration on the Characteristics and Stability of Black Soil Aggregates

作　　者：陈荣桓 余瑶 黄珊 陈荣龙 贾焮凯 陈延华[2] 薛萐 刘萌娟[4] 杨晓梅 CHEN Rong-huan;YU Yao;HUANG Shan;CHEN Rong-long;JIA Xin-kai;CHEN Yan-hua;XUE Sha;LIU Meng-juan;YANG Xiao-mei(College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,China;Institute of Plant Nutrition and Resources,Beijing Academy of Agriculture and Forestry Sciences,Beijing 10009,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,China;College of Agronomy,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]北京市农林科学院植物营养与资源研究所,北京100009 [3]西北农林科技大学水土保持研究所/黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [4]西北农林科技大学农学院,陕西杨凌712100

出　　处：《土壤通报》2023年第1期56-66,共11页Chinese Journal of Soil Science

基　　金：黄土高原土壤侵蚀与旱地农业国家重点实验室基金(A314021402-2017);陕西省人才引进专项(F2020221008)资助。

摘　　要：【目的】微塑料会与土壤颗粒及团聚体相互作用而影响土壤的稳定性,探究微塑料浓度对黑土团聚体特征及其稳定性的影响,以期为农田土壤(微)塑料污染及土壤健康评价提供数据基础。【方法】通过大豆盆栽实验,研究自然条件下不同微塑料浓度(0%、0.1%、0.5%、1%、2%、5%)对黑土团聚体组成、团聚体稳定性(大团聚体含量R> 0.25)、土壤团聚体特征指标(平均质量直径MWD、几何均重直径GMD、分形维数FD)的影响。【结果】不同微塑料浓度处理中,<0.25 mm的机械稳定性团聚体含量比例最小,且> 2 mm和<0.25 mm的团聚体含量比例随着微塑料浓度的增加而增加;> 2 mm的水稳性团聚体含量比例最小,<0.25 mm的水稳性团聚体含量比例随着微塑料浓度的增加而增加;但在1%浓度时,机械稳定性和水稳性团聚体含量比例均与其他浓度的趋势相反;无植物种植的团聚体变化与种植物的相似。土壤大团聚体(R> 0.25)的含量比例随着微塑料浓度的增加而显著减小,当微塑料浓度为1%时,其含量比例略低于对照试验(CK)。不同采样期,大豆成熟期的土壤机械稳定性团聚体和水稳性团聚体的MWD、GMD均比花期的小,而花期的团聚体分形维数比成熟期高,表明随着大豆生长及微塑料的作用,土壤团聚体稳定性降低。通过相关性分析表明,MWD与GMD呈极显著正相关关系,且二者均与FD值呈极显著负相关,即土壤团聚体MWD和GMD总体显著增大,FD值则显著减小,从而表征土壤颗粒团聚性下降。此外,当土壤中微塑料浓度为1%时,土壤团聚体分形维数最小,即土壤团聚作用增强。【结论】土壤中微塑料累积浓度越高,对土壤团聚体产生的破坏作用越强,导致土壤颗粒间聚合能力减弱,土壤中微塑料浓度为1%是否可作为影响黑土团聚体稳定性变化的阈值还有待后续研究,以期为全面评估微塑料对土壤质量的影响提供依据。[Objective] Microplastics interact with soil particles and aggregates and affect soil stability. It is of great significance to investigate the effect of microplastic concentration on the characteristics and stability of black soil aggregates, [Method] Soybean pot experiment was conducted at the different microplastics concentrations l(0%,0.1%, 0.5%, 1%, 2%, 5%) in soil under natural conditions. The indices of aggregates, such as macroaggregate content(R> 0.25), mean weight diameter(MWD), geometric mean diameter(GMD) and fractal dimension(FD) of Black soil aggregates were observed and analyzed. [Result] In different treatments of microplastic concentration, the content proportion of mechanical stable aggregates with particle < 0.25 mm was the lowest, and the content proportion of aggregates with particle > 2 mm and < 0.25 mm increased with the increase of microplastic concentration. The content proportion of water-stable aggregates with particle > 2 mm was the lowest, and the content proportion of water-stable aggregates with particle < 0.25 mm increased with the increase of microplastic concentration. However, the content proportion of mechanical and water stable aggregates was contrary to the trend of other concentrations in the treatment with 1% microplastic. Planting was similar to the change of aggregates without planting. The content proportion of soil macroaggregates(R> 0.25) decreased significantly with the increase of microplastic concentration, except for the content proportion in treatment with 1% of microplastic addition. Regarding to the different sampling periods, the MWD and GMD of soil mechanical and water stable aggregates at soybean maturity stage were lower than that at flowering stage while FD at soybean maturity stage were greater than that at flowering stage, indicating that the stability of soil aggregates reduced with the plant and microplastic interaction. Correlation analysis showed that MWD and GMD were significantly positively correlated, and both of them were significantly negatively

关 键 词：微塑料 土壤团聚体 土壤稳定性 分形维数 

分 类 号：X505[环境科学与工程—环境工程] S153[农业科学—土壤学]