Abstract

Mining activities alter soil physicochemical and biological properties which are critical for plant establishment. Revitalisation of soil biological properties via microbial inoculations can potentially be adopted to improve vegetation restoration. Here, we evaluate the feasibility of using beneficial microorganisms in the form of commercially available inoculants to enhance plant performance in a non-toxic and infertile mine-waste substrate, using pigeon pea (Cajanus cajan [L] Millsp.) as a test plant. Six treatments were established to investigate the effects of inoculants (Bradyrhizobium spp., microbial-mix and uninoculated controls) and water availability (low and moderate) in a factorial design over 6 months. Plant performance was determined by physiological parameters (leaf gas-exchange, leaf carbon, nitrogen and stable isotopes) and growth (height and biomass). Plant xylem sap phytohormones were measured to determine the plants' physiological status and effects of inoculation treatments. Results revealed that water had a greater effect on plant growth than inoculation treatments. Inoculation treatments, however, improved some physiological parameters. This study suggests that physical conditions such as soil moisture and nutrient availability may occlude more subtle (direct or interactive) effects of beneficial soil microbes on plant growth and plant condition. Prior knowledge on the biological and physicochemical properties of the soil to be amended, and on plant species-specific responses, would be needed to customise microbial inoculants for maximum benefits to ecological restoration, to support future adoption of this practice.

Keywords

gas exchange; microbial inoculation; mine site restoration; phytohormones; soil amendments; xylem sap

Published in

Land Degradation and Development
2022, Volume: 33, number: 3, pages: 497-511

SLU Authors

• Yong, Jean W.H

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


Sustainable Development Goals

SDG9 Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation
SDG12 Ensure sustainable consumption and production patterns


UKÄ Subject classification

Botany
Microbiology
Soil Science


Publication identifier

DOI: https://doi.org/10.1002/ldr.4165

Permanent link to this page (URI)

https://res.slu.se/id/publ/114099