Physical Properties of Constructed and Undisturbed Soils

Abstract

AbstractThere is a growing impetus to use soil properties to determine if reclamation efforts are adequate to restore productivity. Constructed mine soils were studied 4 and 11 yr after reclamation to determine physical and hydrological properties. Soils constructed using similar methods and with similar vegetation histories were compared to each other and to an equivalent undisturbed soil. Bulk density was greater in the topsoil and subsoil materials of the constructed soils than in the undisturbed A and B soil horizons. Macropore volume (pore radii > 15 µm) was greater in the topsoil and subsoil materials at the 11‐yr site relative to the 4‐yr site but was significantly lower than that in the undisturbed soil. Small pore volume (pore radii from 4.5 to 0.1 µm) in the reclaimed topsoil materials was similar to the undisturbed A horizon soil but was larger in reclaimed subsoil materials than in the undisturbed B horizon. Saturated hydraulic conductivity (Ks) of the reclaimed topsoil was about 25% that of the undisturbed A horizons and the reclaimed subsoil Ks was less than 10% that of the undisturbed B horizon. The reduction in Ks was attributed to the increase in bulk density and disruption of soil structural units and associated interpedal pore spaces during mining and soil construction. No significant differences in Ks were found between constructed minesoils 4 and 11 yr after reclamation. The results of this study show that soil properties may be useful for evaluating reclamation success after soil construction.