Development of mine soil quality index (MSQI) for evaluation of reclamation success: A chronosequence study

• Mine soil quality index (MSQI) was developed to assess the success of reclamation.
• Selected soil indicators in a chronosequence site were integrated into MSQI.
• MSQI increased with reclamation age.
• MSQI of 17 year old reclaimed site is comparable with the nearby forest site.

Assessment of mine soil quality is the key parameter for evaluation of reclamation success. To investigate the effect of vegetation on mine soil development and reclamation, chronosequence sites were selected in a large opencast coal project in North Karanpura Area, Central Coalfield Limited (CCL), India. The physico-chemical and biological characteristics of chronosequence sites were compared with reference forest site. Principal component analysis (PCA) was employed to derive a mine soil quality index (MSQI) which was used for assessing the progress of reclamation. Soil organic carbon, soil CO2 flux, dehydrogenase activity, coarse soil fraction, moisture content and base saturation are the most critical properties controlling health of reclaimed coal mine soil. The observed values of the above soil indicator parameters were converted into a unitless score (0–1.00) and the scores were integrated into MSQI. The MSQI values were validated by regression analysis with the plant growth parameters (aerial height, diameter at breast height and canopy cover). The contribution of each soil indicator parameter on calculated MSQI was analysed, which gives an insight into the cause for the measured MSQI. The calculated MSQI varied from 0.220 in 2 years old reclaimed dump to 0.670 in 17 years old reclaimed dump. More the MSQI value better is the reclamation status of the mine soil. Mine soil with MSQI > 0.500 may be considered as ecologically sustainable or reclamation is satisfactory. Age of reclamation has been found to have a significant effect on the nutritional and microbial properties of the mine soils. Progressive build up of adequate nutrient pool in 17 year site may be sufficient for ecosystem maintenance in this region.

Figure optionsDownload as PowerPoint slide