Functions of mineral-solubilizing microbes and a water retaining agent for the remediation of abandoned mine sites

Sci Total Environ. 2021 Mar 20:761:143215. doi: 10.1016/j.scitotenv.2020.143215. Epub 2020 Oct 27.

Abstract

There has been a rapid increase in abandoned mines across China, Consequently, external-soil spray seeding technologies have emerged as a common method for their remediation. However, slope soils are typically unstable and easily collapsed and the nutrients absorbed by plants are insufficient, which complicate ecological restoration. For this study, we added mineral-solubilizing microbes and a water retaining agent to an external-soil spray seeding substrate in Lespedeza bicolor pots. We investigated the soil nutrients, soil enzyme activities, root growth parameters, root tensile properties, and root-reinforced soil shear strengths. The results revealed that the addition of microbes enhanced soil nutrients, soil enzyme activities, and the content of lignin and hemicellulose, which promoted root growth. Further, the addition of a water retaining agent promoted Lespedeza bicolor root growth but decreased the root tensile strength and force. Shear stress under the microbe treatment was more robust than without it. Finally, root growth was correlated with soil nutrients and enzyme activities, whereas the root tensile force and strength were correlated with lignin and cellulose. Our results suggested that the addition of mineral-solubilizing microbes had the capacity to enhance the quality of soils to facilitate the growth of plants. These results provide a new and viable strategy for the ecological restoration of abandon mine sites.

Keywords: Mineral-solubilizing microbes and water retaining agent; Root growth parameters; Root tensile properties; Root-reinforced soil shear strength; Soil properties.

MeSH terms

  • China
  • Minerals
  • Soil
  • Soil Microbiology
  • Soil Pollutants* / analysis
  • Water*

Substances

  • Minerals
  • Soil
  • Soil Pollutants
  • Water