Northeast Agricultural University, 600 Changjiang Rd, Harbin, 150030, PR China.
Northeast Agricultural University, 600 Changjiang Rd, Harbin, 150030, PR China.
Chemosphere. 2022 Dec;308(Pt 1):136282. doi: 10.1016/j.chemosphere.2022.136282. Epub 2022 Sep 2.
Mesoplastic (MaP) and macroplastic (MeP) coming from plastic mulching tend to cause negative effects on biota in ecosystems. However, it is still not clear how field management influences the distribution of MeP/MaP in soils. In this study, MeP/MaP was investigated in 0-20 and 20-30 cm soil layers of three vegetable fields (3.4-6.5 ha) after 13 years plastic-mulching in Mollisols of Northeast China under different management methods (MM) of fertilization and tillage frequency. The tillage frequency was MM2 > MM1 > MM3, while the fertilization was MM1 > MM2 > MM3. The results showed that polyethylene (PE), polypropylene (PP), polystyrene, polyvinyl chloride, polyethylene terephthalate (PET), polyamide, melamine-formaldehyde resin and polyether urethane were found in soil, and PE (>83.76%, from plastic mulching) was the predominant type of MeP/MaP. MeP abundance was significantly (p < 0.05) higher in MM1 and MM2 than that in MM3 in the 0-20 cm soil layer. MM1 and MM2 had the highest abundance of MeP/MaP of size <4 cm and 4-16 cm, while MM3 had the highest abundance at the size >16 cm. The broken index of MeP/MaP was significantly (p < 0.05) lower in MM2 compared with MM1 and MM3 in the 20-30 cm soil layer. Both tillage frequency and fertilization accelerate the breaking of plastics, especially since the influence was stronger from fertilization. Compared with original plastics, the PE, PP and PET's carbonyl index was significantly (p < 0.05) higher in the three MMs. Generally, fertilization and frequent tillage can reduce the physical effects of large-sized plastic debris on crop growth and increases the negative effects of small-sized plastic and new pollutants formed on biota in the agroecosystems. MeP/MaP recycling should be strengthened, and the irrigation and rotation of farmland should be carried out when the wind speed is weak to avoid plastic invasion.
农田残膜中的中高分子量塑料（MaP）和高分子量塑料（MeP）会对生态系统中的生物产生负面影响。然而，田间管理如何影响土壤中 MeP/MaP 的分布尚不清楚。本研究在中国东北黑土区，采用完全随机区组设计，在 3 个蔬菜地（3.4-6.5 公顷）中，设置 3 种不同施肥和耕作频率管理措施（MM），连续覆膜 13 年后，研究了 0-20 和 20-30 cm 土层中 MeP/MaP 的分布。耕作频率为 MM2 > MM1 > MM3，施肥水平为 MM1 > MM2 > MM3。结果表明，土壤中检测到了聚乙烯（PE）、聚丙烯（PP）、聚苯乙烯、聚氯乙烯、聚对苯二甲酸乙二醇酯（PET）、聚酰胺、密胺-甲醛树脂和聚醚型聚氨酯等塑料，其中来源于塑料地膜的 PE（83.76%）是 MeP/MaP 的主要类型。在 0-20 cm 土层中，MM1 和 MM2 中 MeP 的丰度显著（p < 0.05）高于 MM3。MM1 和 MM2 中尺寸 <4 cm 和 4-16 cm 的 MeP/MaP 丰度最高，而 MM3 中尺寸 >16 cm 的 MeP/MaP 丰度最高。20-30 cm 土层中，MM2 的 MeP/MaP 破碎指数显著（p < 0.05）低于 MM1 和 MM3。耕作频率和施肥都加速了塑料的破碎，特别是施肥的影响更强。与原始塑料相比，3 个 MM 中 PE、PP 和 PET 的羰基指数均显著（p < 0.05）升高。总的来说，施肥和频繁耕作可以减少大尺寸塑料碎片对作物生长的物理影响，增加小尺寸塑料和新形成的污染物对农业生态系统中生物的负面影响。应加强对 MeP/MaP 的回收利用，在风速较弱时进行灌溉和轮作，以避免塑料侵入。
