Effects of biodegradable and conventional microplastics on soil-mung bean system under ZnO nanoparticle stress
摘要
The plastic film mulch and nano-fertilization were widely used in agricultural production, which caused co-input of microplastics (MPs) and ZnO nanoparticles (ZnO NPs) into agricultural soil, but few studies have focused on co-exposure of ZnO NPs and different MPs. Here we concentrated on assessing the effects of co-exposure of ZnO NPs and conventional polyethylene (PE)/bio-degradable polylactide (PLA) microplastics on soil–plant system.
MethodsThe individual and combined of ZnO NPs and PE/PLA microplastics were applied to mung bean. Plant physiological, antioxidant enzyme activities, element absorption were assessed, alongside changes in soil microbial communities and physicochemical properties.
ResultsThe addition of individual MPs and co-exposure of MPs and ZnO NPs did not pose significant effects on root and shoot DW compared to control (CK), while the individual exposure of ZnO NPs significantly decreased the the root dry weight (DW) compared with the CK and MPs treatments. The addition of two types of MPs increased root Zn concentration (+ 28.46% to + 39.18%) and decreased its concentration in leaves (–2.3% to –8.07%) compared to ZnO NPs alone. The family Xanthomonadaceae was the most important soil bacteria influencing Zn concentration in mung bean. The conventional PE mainly enhanced the C fixation and N reduction functional microbiome, whereas PLA tended to enrich C degradation and predatory or exoparasitic microbiome for N cycle.
ConclusionsThese findings revealed the combined and individual effects of two types of MPs and ZnO NPs stress on soil properties and microbial environment and mung bean growth. These findings advance understanding of integrated plant-soil response under the co-usage of ZnO NPs fertilizer and plastic film mulch.