Management of topsoil for geoenvironmental reclamation of coal mining areas

Topsoil is an essential component for land reclamation in mining areas. It is seriously damaged if it is not mined out separately without being contaminated, eroded and protected. Systematic handling and storage practices can protect topsoil while in storage and after it has been redistributed onto the regraded area. Impact of coal mining on topsoil quality in Indian context has been described. Systematic removal of topsoil, its storage practice, geometry of topsoil heap are discussed in this study. Removed topsoil should be reclaimed technically and its shelf-life period should be ascertained. To assess the shelf-life period, an investigation was conducted in a large opencast coal project. Soil dumps of different age classes in the area were identified and analyzed critically to evaluate the deterioration of soil quality with respect to time, and compared with those of unmined areas. Changes in soil quality showed a continuous decrease every year and ultimately became biologically sterile. Biological reclamation is essential if the soil is to be stored beyond the shelf-life period. Preservation of stockpiled topsoil, its redistribution on the regraded areas, nutrients and amendments to be added, are discussed briefly in this study.