TY - JOUR

T1 - Microplastics as an emerging threat to plant and soil health in agroecosystems

AU - Zhou, Jie

AU - Wen, Yuan

AU - Marshall, Miles R.

AU - Zhao, Jie

AU - Gui, Heng

AU - Yang, Yadong

AU - Zeng, Zhaohai

AU - Jones, Davey L.

AU - Zang, Huadong

PY - 2021/9/15

Y1 - 2021/9/15

N2 - Microplastics (MPs, <5 mm in diameter) have been widely recognized as a critical environmental issue due to their extensive use and low degradation rate. Based on current evidence, our aim is to evaluate whether MPs represent an emerging threat to plant-soil health in agroecosystems. We assess the ecological risks to plant-microbe-soil interactions associated with MPs and discuss the consequences of MPs on soil carbon (C), nutrient cycling, as well as greenhouse gas emissions in agroecosystems. We also identify knowledge gaps and give suggestions for future research. We conclude that MPs can alter a range of key soil biogeochemical processes by changing its properties, forming specific microbial hotspots, resulting in multiple effects on microbial activities and functions. Mixed effects of MPs on plant growth and performance can be explained by the direct toxicity of MPs or the indirect alteration in soil physical structures and microbial communities (i.e. symbiotic arbuscular mycorrhizal fungi). Because of the diverse nature of MPs found in soils, in terms of polymer type, shape and size, we also see differing effects on soil organic matter (SOM) decomposition, nutrient cycling, and greenhouse gases production. Importantly, increased bioavailable C from the decomposition of biodegradable MPs, which enhances microbial and enzymatic activities, potentially accelerates SOM mineralization and increases nutrient competition between plant and microbes. Thus, biodegradable MPs appear to pose a greater risk to plant growth compared to petroleum-based MPs. Although MPs may confer some benefits in agroecosystems (e.g. enhanced soil structure, aeration), it is thought that these will be far outweighed by the potential disbenefits.

AB - Microplastics (MPs, <5 mm in diameter) have been widely recognized as a critical environmental issue due to their extensive use and low degradation rate. Based on current evidence, our aim is to evaluate whether MPs represent an emerging threat to plant-soil health in agroecosystems. We assess the ecological risks to plant-microbe-soil interactions associated with MPs and discuss the consequences of MPs on soil carbon (C), nutrient cycling, as well as greenhouse gas emissions in agroecosystems. We also identify knowledge gaps and give suggestions for future research. We conclude that MPs can alter a range of key soil biogeochemical processes by changing its properties, forming specific microbial hotspots, resulting in multiple effects on microbial activities and functions. Mixed effects of MPs on plant growth and performance can be explained by the direct toxicity of MPs or the indirect alteration in soil physical structures and microbial communities (i.e. symbiotic arbuscular mycorrhizal fungi). Because of the diverse nature of MPs found in soils, in terms of polymer type, shape and size, we also see differing effects on soil organic matter (SOM) decomposition, nutrient cycling, and greenhouse gases production. Importantly, increased bioavailable C from the decomposition of biodegradable MPs, which enhances microbial and enzymatic activities, potentially accelerates SOM mineralization and increases nutrient competition between plant and microbes. Thus, biodegradable MPs appear to pose a greater risk to plant growth compared to petroleum-based MPs. Although MPs may confer some benefits in agroecosystems (e.g. enhanced soil structure, aeration), it is thought that these will be far outweighed by the potential disbenefits.

KW - Microplastics

KW - Plant growth

KW - Soil carbon storage

KW - Nutrient cycling

KW - Greenhouse gas emissions

KW - Biodegradable plastics

KW - Agroecosystem

U2 - 10.1016/j.scitotenv.2021.147444

DO - 10.1016/j.scitotenv.2021.147444

M3 - Review article

VL - 787

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

M1 - 147444

ER -