Revegetation of extremely acid mine soils based on aided phytostabilization: A case study from southern China

- An effort was made to revegetate an extremely acid (pH < 3) mine soil.
- Net acid-generating potential of the mine soil decreased steadily with time.
- Soil pH and acid neutralization capacity increased gradually with time.
- Plants survived, grew and developed a good vegetation cover within 6 months.
- The vegetation development enhanced nutrient accumulation in the mine soil.

Acidification is a major constraint for revegetation of sulphidic metal-contaminated soils, as exemplified by the limited literature reporting the successful phytostabilization of mine soils associated with pH < 3 and high acidification potential. In this study, a combination of ameliorants (lime and chicken manure) and five acid-tolerant plant species has been employed in order to establish a self-sustaining vegetation cover on an extremely acid (pH < 3) polymetallic pyritic mine waste heap in southern China exhibiting high acidification potential. The results from the first two-year data showed that the addition of the amendments and the establishment of a plant cover were effective in preventing soil acidification. Net acid-generating potential of the mine soil decreased steadily, whilst pH and acid neutralization capacity increased over time. All the five acid-tolerant plants colonized successfully in the acidic metal-contaminated soil and developed a good vegetation cover within six months, and subsequent vegetation development enhanced organic matter accumulation and nutrient element status in the mine soil. The two-year remediation program performed on this extremely acid metalliferous soil indicated that aided phytostabilization can be a practical and effective restoration strategy for such extremely acid mine soils.

Acidification is a major constraint for revegetation of sulphidic metal-contaminated soils, as exemplified by the lack of literature reporting the successful phytostabilization of mine soils associated with pH < 3 and high acidification potential.420