Synergistic backfilling and revegetation approaches for ecological reclamation of small-scale sandstone mine pits in...

Abandoned sandstone mines pose significant threats to the environment and safety. Despite the threats, the mined-out pits in arid areas of Rajasthan remain unreclaimed. The major challenges associated with the reclamation of these degraded lands include lack of awareness, harsh climatic conditions, low water availability, and the unavailability of abundant backfilling materials, coupled with topsoil deficit and nutrient-poor conditions. Reclamation of small-scale sandstone mines remains underexplored in scientific literature, limiting the development of evidence-based restoration strategies. Therefore, this review synthesizes the possible approaches for active reclamation of sandstone mined-out pits in the arid regions of Rajasthan. The key steps of active reclamation of the exhausted mine pits are topographic reconstruction through backfilling, topsoil application, soil amendments, and phytorestoration. This manuscript extensively explored the utilization of non-hazardous industrial waste as sustainable backfilling materials, different soil amendments in the context of the backfilled mine land, and revegetation strategies. In our view, the selection of native species is the most critical step of the revegetation strategy, closely followed by post plantation care. In addition, microbial interventions, especially the inoculation of beneficial microbes like plant growth-promoting bacteria, mycorrhiza, and others, have been discussed for promoting soil health and enhancing plant growth.