Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, People's Republic of China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, People's Republic of China; Research Center for Environmental Ecology and Engineering, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, 206 Guanggu 1st Road, Wuhan 430205, People's Republic of China.
Research Center for Environmental Ecology and Engineering, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, 206 Guanggu 1st Road, Wuhan 430205, People's Republic of China.
J Hazard Mater. 2022 Jun 15;432:128721. doi: 10.1016/j.jhazmat.2022.128721. Epub 2022 Mar 17.
The accumulation of microplastics (MPs) in terrestrial ecosystems can affect greenhouse gases (GHGs) production by changing soil structure and microbial functions. In this study, microcosm experiments were conducted to investigate the impact of polyethylene (PE) MP addition on soil carbon dioxide (CO) and nitrous oxide (NO) emissions from paddy soils and their associated microbial functional genes. Methane was not considered due to the negligible emissions throughout the incubation. The amendment of both virgin and aged PE MPs did not significantly (p > 0.05) affect soil CO emissions, but significantly (p < 0.05) increased the abundances of microbial functional genes encoding enzymes involved in hemicellulose (abfA) and lignin (mnp) decomposition, indicating plastic particle has potential to stimulate soil organic carbon decomposition. The presence of PE MP significantly increased NO emissions by 3.7-fold, which was probably due to PE MP increased the abundances of nirS gene involved in nitrite reductase. In addition, compared with virgin PE MP treatment, artificially aged PE MP did not significantly (p > 0.05) influence soil CO and NO emissions. Our results provide evidence that PE MP likely cause a high risk of NO emission from paddy soils, this factor should be considered in future estimates of GHGs emissions from rice fields.
微塑料（MPs）在陆地生态系统中的积累会改变土壤结构和微生物功能，从而影响温室气体（GHGs）的产生。本研究采用微宇宙实验，研究了添加聚乙烯（PE） MPs 对稻田土壤二氧化碳（CO）和氧化亚氮（NO）排放及其相关微生物功能基因的影响。由于在整个培养过程中甲烷排放量可忽略不计，因此不考虑甲烷。原始和老化的 PE MPs 的添加均未显著（p>0.05）影响土壤 CO 排放，但显著（p<0.05）增加了参与半纤维素（abfA）和木质素（mnp）分解的酶的微生物功能基因的丰度，表明塑料颗粒具有刺激土壤有机碳分解的潜力。PE MP 的存在使 NO 排放增加了 3.7 倍，这可能是由于 PE MP 增加了参与亚硝酸盐还原酶的 nirS 基因的丰度。此外，与原始 PE MP 处理相比，人工老化的 PE MP 对土壤 CO 和 NO 排放没有显著影响（p>0.05）。我们的研究结果表明，PE MP 可能会导致稻田中 NO 排放的高风险，在未来对稻田 GHGs 排放的估计中应考虑这一因素。
