Surface mining and reclamation: Initial changes in soil character

ABSTRACT:

Five different, newly reconstructed soil units on surface-mined land and three undisturbed (cultivated, but not mined) soil units were defined and characterized. Selected properties of the reclaimed soils were compared with those of nearby undisturbed soils to determine what changes took place during the mining and reclamation operations. The properties of the five constructed soil units were closely related to premining overburden characteristics and method of soil construction. Comparisons of each of the eight soil units emphasized differences between constructed soils and undisturbed soils, between mining sites, and between topsoil and spoil units within each of the mining sites. Compared with the undisturbed soils, the constructed soils had higher bulk densities and lacked structure. Both the undisturbed soils and constructed soils had moderately fine textures. Organic carbon levels were lower for the constructed soils except in the surfaces of the units that had been topsoiled. In general, the pH, exchangeable calcium levels, and exchangeable sodium levels were higher and the exchangeable magnesium levels were equal or higher in the constructed soils than in the natural soils. The properties of the constructed soils reflect premining overburden character and method of soil construction, suggesting that considerable control over postmine soil characteristics can be managed by careful selection of materials and material-handling methods.