Feasibility of storing topsoil in coal mining areas without biological reclamation

摘要

Opencast mining results in the formation of large overburden and huge voids at the mining sites. Topsoil is a very important component for due reclamation of the area. It is to be preserved properly to protect from erosion and maintaining its fertility status. Indian coal mining scenario has been described indicating its share from opencast mining, land damage, overburden volume etc. Studies were conducted in a large opencast project to investigate the feasibility of strong topsoil without biological reclamation. Different age classes of soil dumps were identified and the deterioration in the 'soil physico-chemical, water retention, fertility status and microbiological activities have been critically analysed with respect to the unmined soil. Correlation coefficients among the different parameters were found to be significantly and positively correlated. Stockpiling of soil material was found to degrade soil quality continually every year and ultimately it became biologically sterile. Topsoil should be removed in a separate layer and should be stockpiled only when it is not feasible to promptly redistribute on re-graded areas. Stockpiled materials should be selectively placed on a suitable area and its technical reclamation has been discussed. The optimum period of storing topsoil without major biological reclamation has been evaluated.