Plastic mulch debris in rhizosphere: Interactions with soil-microbe-plant systems

Yin Liu; Wen Hu; Qing Huang; Jiemin Qin; Yingrui Zheng; Junfeng Wang; Xiaohui Li; Qingqing Wang; Genmao Guo; Shan Hu

doi:10.1016/j.scitotenv.2021.151435

Plastic mulch debris in rhizosphere: Interactions with soil-microbe-plant systems

Sci Total Environ. 2022 Feb 10;807(Pt 2):151435. doi: 10.1016/j.scitotenv.2021.151435. Epub 2021 Nov 6.

Authors

Yin Liu¹, Wen Hu¹, Qing Huang², Jiemin Qin¹, Yingrui Zheng¹, Junfeng Wang³, Xiaohui Li⁴, Qingqing Wang¹, Genmao Guo¹, Shan Hu¹

Affiliations

¹ Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China.
² Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China. Electronic address: huangqing@hainanu.edu.cn.
³ Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China; College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, Guangdong 518061, China.
⁴ Hainan Inspection and Detection Center for Modern Agriculture, Haikou, Hainan 570100, China.

PMID: 34752868
DOI: 10.1016/j.scitotenv.2021.151435

Abstract

Large amounts of plastic mulch debris (PMD) accumulated in the soil can endanger agroecosystems. However, little is known about the interactions between PMD and soil-microbe-plant systems. In this study, a pot experiment (four replicates) in tropical greenhouse was conducted to investigate the effects of PMD (polyethylene) at different concentrations (0, 0.4, 0.8, 4.0, 6.0 g kg^-1) on soil nutrients, rhizosphere bacterial communities and rice growth. This study further explored the interactive mechanisms between PMD and environmental factors based on correlation analysis and previous studies. The results showed that PMD continuously reduced the soil capabilities to store nutrients (C, N, P, humic-like substances) and increased the proportion of P and biodegradable dissolved organic matter (DOM). At the full ripening stage of rice growth, total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in all PMD treatments significantly decreased by 60.86, 52.51 and 34.83% respectively as compared to CK (p < 0.05). Furthermore, PMD increased the total abundance of bacteria but reduced the diversity and evenness of bacterial communities, which further affected microbial metabolic functions. Total OTUs and Shannon decreased 0.02-17.05% and 0.69-7.55% in treatments. At harvest-time, PMD reduced the biomass and yield of rice with 11.34 and 19.24% (all treatments on average) lower than CK. Under the influence of PMD, the order of correlation size between PMD and one environmental factor was PMD-soil > PMD-microbe > PMD-plant, and the order of correlation between two environmental factors was soil-microbe > microbe-plant > soil-plant. Over all, PMD had the most significant negative effects on soil nutrients storage, followed by the change of microbial community structure and microbial metabolic functions. The negative effects of PMD on crops were relatively weak.

Keywords: Agroecosystem; Plastic mulch debris; Rhizosphere microbiome; Rice growth; Soil nutrient.

MeSH terms

Dissolved Organic Matter
Plastics
Polyethylene
Rhizosphere*
Soil*

Substances

Dissolved Organic Matter
Plastics
Soil
Polyethylene