Effects of plastic mulching on the accumulation and distribution of macro and micro plastics in soils of two farming systems in Northwest China

PeerJ

article

Fanrong Meng¹  Tinglu Fan³  Xiaomei Yang¹  Michel Riksen¹  Minggang Xu²  Violette Geissen¹ 

[1]Soil Physics and Land Management, Wageningen University

[2]National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences

[3]Dryland Agriculture Institute, Gansu Academy of Agricultural Sciences

[4]College of Natural Resources and Environment, Northwest A&F University

关键词: Plastic film mulching;    Microplastics;    Farming systems;    Soil pollution;    Low-density polyethylene;   

DOI  :  10.7717/peerj.10375

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Background Inappropriate disposal of the plastic mulching debris could create macroplastics (MaPs) and microplastics (MiPs) pollution in agricultural soil. Methods To study the effects of farming systems on accumulation and distribution of agricultural plastic debris, research was carried out on two farming systems in Northwest China. Farming in Wutong Village (S1) is characterized by small plots and low-intensity machine tillage while farming in Shihezi (S2) is characterized by large plots and high-intensity machine tillage. In September 2017, we selected six fields in S1, three fields with 6–8 years of continuous plastic mulching (CM) as well as three fields with over 30 years of intermittent mulching (IM). In S2, we selected five cotton fields with 6, 7, 8, 15 and 18 years of continuous mulching. In both regions, MaPs and MiPs from soil surface to 30 cm depth (0–30 cm) were sampled. Results The results showed that in S1, MaPs mass in fields with 6–8 years CM (i.e., 97.4kg·ha−1) were significantly higher than in fields with 30 years IM (i.e., 53.7 kg·ha−1). MaPs in size category of 10–50 cm2 accounted for 46.9% in fields of CM and 44.5% in fields of IM of total collected MaPs number. In S2, MaPs mass ranged from 43.5 kg·ha−1 to 148 kg·ha−1. MaPs in size category of 2–10 cm2 account for 41.1% of total collected MaPs number while 0.25–2 cm2 accounted for 40.6%. MiPs in S1 were mainly detected in fields with over 30 years of intermittent mulching (up to 2,200 particles·kg−1 soil), whereas in S2 were detected in all fields (up to 900 particles·kg−1 soil). The results indicated farming systems could substantially affect the accumulation and distribution of agricultural plastic debris. Continuous plastic mulching could accumulate higher amount of MaPs than intermittent plastic mulching. High-intensity machine tillage could lead to higher fragmentation of MaPs and more severe MiPs pollution. These results suggest that agricultural plastic regulations are needed.

【 授权许可】

CC BY