Meng Fanrong, Fan Tinglu, Yang Xiaomei, Riksen Michel, Xu Minggang, Geissen Violette
Soil Physics and Land Management, Wageningen University, Wageningen, The Netherlands.
National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
PeerJ. 2020 Dec 1;8:e10375. doi: 10.7717/peerj.10375. eCollection 2020.
Inappropriate disposal of the plastic mulching debris could create macroplastics (MaPs) and microplastics (MiPs) pollution in agricultural soil.
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.
The results showed that in S1, MaPs mass in fields with 6-8 years CM (i.e., 97.4kg·ha) were significantly higher than in fields with 30 years IM (i.e., 53.7 kg·ha). MaPs in size category of 10-50 cm 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 to 148 kg·ha. MaPs in size category of 2-10 cm account for 41.1% of total collected MaPs number while 0.25-2 cm 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 soil), whereas in S2 were detected in all fields (up to 900 particles·kg 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.
塑料地膜碎片处置不当会造成农业土壤中的大塑料（MaPs）和微塑料（MiPs）污染。
为研究耕作制度对农业塑料碎片积累和分布的影响，在中国西北的两种耕作制度上开展了研究。梧桐村（S1）的耕作特点是地块小且机械耕作强度低，而石河子（S2）的耕作特点是地块大且机械耕作强度高。2017年9月，我们在S1选取了6块田地，3块连续覆膜6 - 8年的田地以及3块间歇覆膜30年以上的田地。在S2，我们选取了5块连续覆膜6年、7年、8年、15年和18年的棉田。在两个地区，对土壤表层至30厘米深度（0 - 30厘米）的大塑料和微塑料进行了采样。
结果表明，在S1，连续覆膜6 - 8年的田地中大塑料质量（即97.4千克·公顷）显著高于间歇覆膜30年的田地（即53.7千克·公顷）。10 - 50厘米尺寸类别的大塑料在连续覆膜田地中占总收集大塑料数量的46.9%，在间歇覆膜田地中占44.5%。在S2，大塑料质量在43.5千克·公顷至148千克·公顷之间。2 - 10厘米尺寸类别的大塑料占总收集大塑料数量的41.1%，而0.25 - 2厘米尺寸类别占40.6%。S1中的微塑料主要在间歇覆膜30年以上的田地中检测到（高达2200个颗粒·千克土壤），而在S2中所有田地均检测到（高达900个颗粒·千克土壤）。结果表明耕作制度会显著影响农业塑料碎片的积累和分布。连续塑料覆膜比间歇塑料覆膜积累的大塑料量更高。高强度机械耕作会导致大塑料更高程度的破碎和更严重的微塑料污染。这些结果表明需要制定农业塑料相关规定。
