School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China; Engineering Research Center of Biomass Materials, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China.
J Hazard Mater. 2022 Feb 5;423(Pt A):127062. doi: 10.1016/j.jhazmat.2021.127062. Epub 2021 Aug 29.
Polyethylene film is the most widely used plastic film in agricultural production activities, and its depolymerization products are mainly polyethylene-particles (PE-particles) of different molecular weights. However, the impact of the molecular weights of the PE-particles on soil-crop microenvironment has not been elucidated. In this study, a potted microcosmic simulation system was used to evaluate the impact of low, medium and high molecular weight PE-particles on soil metabolism, microbial community structure, and crop growth. There were obvious differences in the shape and surface microstructure of PE-particles with different molecular weights. Soil sucrase and peroxidase had significant responses to PE-particles of different molecular weights. In the rhizosphere, the number of microorganisms and the microbial alpha diversity index increased with increasing PE-particles molecular weight. Rhizobacter, Nitrospira, and Sphingomonas were the dominant microorganisms induced by PE-particles to regulate the metabolism of elements. Carbohydrate and amino acid contents in rhizosphere soils were the key factors affecting the species abundance of Lysobacter, Polyclovorans, Rhizobacter, and Sphingomonas. In plants, PE-particles treatment reduced the plant biomass and photosynthetic rate and disrupted normal mineral nutrient metabolism. Different molecular weight PE-particles may therefore have adverse effects on the soil-plant system.
聚乙烯薄膜是农业生产活动中应用最广泛的塑料薄膜，其解聚产物主要为不同分子量的聚乙烯颗粒（PE 颗粒）。然而，PE 颗粒的分子量对土壤-作物微环境的影响尚未阐明。本研究采用盆栽微宇宙模拟系统，评估了低、中、高分子量 PE 颗粒对土壤代谢、微生物群落结构和作物生长的影响。不同分子量的 PE 颗粒在形状和表面微观结构上存在明显差异。土壤蔗糖酶和过氧化物酶对不同分子量的 PE 颗粒有明显的响应。在根际区，微生物数量和微生物 α 多样性指数随 PE 颗粒分子量的增加而增加。根际菌、硝化螺旋菌和鞘氨醇单胞菌是 PE 颗粒诱导的调节元素代谢的优势微生物。根际土壤中碳水化合物和氨基酸含量是影响赖氨酸杆菌、聚球藻菌、根际菌和鞘氨醇单胞菌物种丰度的关键因素。在植物中，PE 颗粒处理降低了植物生物量和光合速率，破坏了正常的矿物质营养代谢。因此，不同分子量的 PE 颗粒可能对土壤-植物系统产生不利影响。
