Coupled pot and lysimeter experiments assessing plant performance in microbially assisted phytoremediation.

Area of Science:

• Environmental Science
• Soil Science
• Microbiology

Background:

• Tailing dam substrates pose challenges for plant establishment due to poor nutrient content and potential toxicity.
• Plant growth-promoting bacteria (PGPB) are known to enhance plant growth in various environments.

Purpose of the Study:

• To assess the efficacy of PGPB in promoting the growth of five plant species on tailing dam substrate.
• To evaluate the impact of PGPB inoculation on soil properties and element bioavailability at different experimental scales.

Main Methods:

• Pot and lysimeter scale experiments were conducted using five plant species on tailing dam substrate amended with compost.
• Inoculation with PGPB was applied, and plant biomass, soil respiration, and element concentrations in leachate and plant tissues were measured.
• Plant oxidative stress markers were also assessed.

Main Results:

• PGPB inoculation, combined with compost amendment, significantly increased plant biomass for Agrostis capillaris and Festuca rubra.
• Inoculation led to increased soil respiration and element immobilization at the root surface, decreasing element concentrations in leachate.
• Metal concentrations in plant roots decreased, while phosphorus increased in inoculated plants; scale differences were observed in soil respiration and leachate/plant element concentrations.

Conclusions:

• A system combining Agrostis capillaris, compost, and PGPB from native rhizosphere can be a viable option for tailing dam phytostabilization.
• Further field-scale investigations are recommended to validate these findings.