College of Resources, Hunan Agricultural University, Changsha, 410128, China; National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Changsha, 410128, China; Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
College of Resources, Hunan Agricultural University, Changsha, 410128, China; National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Changsha, 410128, China.
Environ Pollut. 2024 Nov 1;360:124702. doi: 10.1016/j.envpol.2024.124702. Epub 2024 Aug 8.
In recent years, as the abundance of residual mulch film (RMF) in agricultural soil continues to increase, whether the adsorption capacity of its surface affects the migration of heavy metals is a topic of current interest for scholars. Herein, this study investigated the distribution of RMF abundance and metal concentration in different soil layers of 75 plastic-mulching croplands in subtropical China; meanwhile, we also explored the associations of RMF characteristics with metal concentration. The results showed that land type, film mulching amount, and film mulching time were the main factors affecting RMF abundance, distribution, and particle size composition. The highest abundance of RMF was found in the garden soils (910 n·kg) with more than 15 years mulching period and more than 19.5 kg hm of annual mulch amount. The lowest abundance of RMF was occurred in the group of field and conservation agricultural land (237 n·kg). Moreover, the concentrations of metals in soil, especially Cd, Cr, Cu, and Pb, were closely related to the extent of RMF contamination in the soil environment. In the 0-10 cm and 10-20 cm soil layers, microplastic abundance exhibited a negative correlation with Cr and Cu concentrations and a positive correlation with Pb concentration. Based on the above findings, it is demonstrated that RMF significantly influences the mobility of metals in soil via adsorption processes, with potential synergistic effects between RMF and heavy metals posing a heightened risk to the soil environment.
近年来，随着农业土壤中残留地膜（RMF）的大量增加，其表面的吸附能力是否会影响重金属的迁移，成为学者们关注的一个课题。本研究调查了中国亚热带地区 75 个塑料地膜农田中不同土层中 RMF 的丰度和金属浓度的分布情况；同时，还探讨了 RMF 特性与金属浓度之间的关系。结果表明，土地类型、地膜用量和地膜使用时间是影响 RMF 丰度、分布和粒径组成的主要因素。覆膜 15 年以上、年覆膜量超过 19.5 kg·hm 的园地土壤中 RMF 含量最高（910 n·kg）。覆膜量最少的是农田和保护性农业用地（237 n·kg）。此外，土壤中金属的浓度，特别是 Cd、Cr、Cu 和 Pb 的浓度，与土壤环境中 RMF 污染的程度密切相关。在 0-10 cm 和 10-20 cm 土层中，微塑料丰度与 Cr 和 Cu 浓度呈负相关，与 Pb 浓度呈正相关。基于上述发现，表明 RMF 通过吸附过程显著影响土壤中金属的迁移，RMF 与重金属之间的协同作用对土壤环境构成了更高的风险。
