Biochar alleviated the toxic effects of PVC microplastic in a soil-plant system by upregulating soil enzyme activities and microbial abundance

Environ Pollut. 2023 Sep 1:332:121810. doi: 10.1016/j.envpol.2023.121810. Epub 2023 May 16.

Abstract

Plastics have become an emerging pollutant threatening the sustainability of agroecosystems and global food security. Biochar, a pro-ecosystem/negative carbon emission technology can be exploited as a circular approach for the conservation of plastics contaminated agricultural soils. However, relatively few studies have focused on the effects of biochar on plant growth and soil biochemical properties in a microplastic contaminated soil. This study investigated the effects of a cotton stalk (Gossypium hirsutum L.) biochar on plant growth, soil microbes, and enzyme activity in PVC microplastic (PVC-MPs) contaminated soil. Biochar amendment increased shoot dry matter production in PVC-MPs contaminated soil. However, PVC-MPs alone significantly reduced the soil urease and dehydrogenase activity, soil organic and microbial biomass carbon, bacterial/fungal community percentage, and their abundance (16S rRNA and 18S rRNA genes, respectively). Interestingly, biochar amendment with PVC-MPs significantly alleviated the hazardous effects. Principal component and redundancy analysis of the soil properties, bacterial 16S rRNA genes, and fungal ITS in the biochar-amended PVC-MPs treatments revealed that the observed traits formed an obvious cluster compared to non-biochar treatments. To sum up, this study indicated that PVC-MPs contamination was not benign, while biochar shielded the hazardous effects and sustained soil microbial functionality.

Keywords: Dehydrogenase; PLFA biomarkers; Plastics; Polyvinyl chloride; Urease.

MeSH terms

  • Carbon
  • Charcoal / chemistry
  • Charcoal / pharmacology
  • Ecosystem
  • Microplastics*
  • Plastics
  • RNA, Ribosomal, 16S
  • Soil / chemistry
  • Soil Microbiology
  • Soil Pollutants* / chemistry
  • Soil Pollutants* / toxicity

Substances

  • Microplastics
  • Plastics
  • Soil
  • RNA, Ribosomal, 16S
  • biochar
  • Charcoal
  • Carbon
  • Soil Pollutants