ABSTRACT Land degradation caused by surface mining of gold has been extensive in Ghana. In recent years rehabilitation of some degraded lands by re-vegetation has been undertaken. This study provides quantitative data on the quality of some rehabilitated and un-rehabilitated mined soils within the AngloGold-Ashanti gold concession in parts of the semi-deciduous forest zone of Ghana. Soil properties determined included texture, bulk density and aggregate stability, pH, organic carbon, available phosphorus, total nitrogen, cation exchange capacity, exchangeable bases, exchange acidity, Fe, Mn, Ni, Cu, Zn, Cd, and Pb. Aggregate stability as a physical quality indicator revealed that aggregates of the rehabilitated mined soil had become more stable and similar to the control unmined soil due to litter and carbon additions from planted trees. The nutrient levels were very low because of the presence of low activity clays inherent in the native soil. Organic carbon content in the rehabilitated soil had increased above that of the unrehabilitated soil. Variability in soil properties, especially organic carbon and aggregate stability, was minimal in the unmined and rehabilitated soils implying that soils at the two sites were most robust and resistant to crushing and rupture. Quality index of the unmined control soil was 36.5% indicating that the quality of the soil was 63.5% relative to the optimum quality because of inherent poor soil properties. The mined rehabilitated and unrehabilitated soil had index values of 32.5% and 24.4 %, respectively. The marginal difference of 4% in soil quality between the control and rehabilitated soil shows that it is possible to maintain the health of soils with inherent physical and biochemical deficiencies if reclamation regulations are adhered to. In this way, the socio-economic dilemma of exploiting natural resources for the benefit of societies is ameliorated while maintaining an ecosystem balance.
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W. Dorgbetor, G. Dowuona, S. Danso, J. Amatekpor, A. Ogunkunle and E. Boateng, "Evaluation of Quality of Some Rehabilitated Mined Soils within the AngloGold-Ashanti Concession in Ghana," International Journal of Geosciences, Vol. 3 No. 1, 2012, pp. 50-61. doi: 10.4236/ijg.2012.31007.
 R. J. Van Aarde, A. M. Smit and A. S. Claassens, “Soil Characteristics of Rehabilitating Mined and Unmined Coastal Dunes at Richards Bay, KwaZulu-Natal, South Africa,” Restoration Ecology, Vol. 6, No. 1, 1998, pp. 102-110. doi:10.1046/j.1526-100x.1998.06113.x
 E. Callender, “Heavy Metals in the Environment –Historical Trends,” In: B. S. Lollar, Ed., Treatise on Geochemistry, Environmental Geochemistry, Elsevier, Amsterdam, 2004, pp. 67-105.
 A. Hüttermann, I. Arduini and D. L. Godbold, “Metal Pollution and Forest Decline,” In: M. N. V. Prasad, Ed., Heavy Metal Stress in Plants from Biomolecules to Ecosystems, 2nd Edition, Springer-Verlag, Berlin, 2004, pp. 295-312.
 K. Telmera, M. Costa, R. Angélica, E. S. Araujof and Y. Mauriceg, “The Source and Fate of Sediment and Mercury in the Tapajós River Para, Brazilian Amazon: Ground- and Space-based Evidence,” Journal of Environmental Management, Vol. 81, No. 2, 2006, pp. 101-113.
 Australian Environment Protection Agency, “Rehabilitation and Revegetation, Best Practice Environmental Management in Mining,” ACT7 Commonwealth of Australia, Barton, 1995.
 W. H. O. Ernst, “Bioavailability of Heavy Metals and Decontamination of Soils by Plants,” Applied Geochemistry, Vol. 11, No. 1-2, 1996, pp. 163-167.
 D. C. Adriano, “Trace Elements in Terrestrial Environments: Biogeochemistry, Bioavailability and Risk of Metals,” Springer-Verlag, New York, 2001.
 J. F. Parr, R. I. Papendick, S. B. Hornick and R. E. Meyer, “Soil Quality: Attributes and Relationship to Alternative and Sustainable Agriculture,” American Journal of Alternative Agriculture, Vol. 7, No. 1-2, 1992, pp. 5-11.
 US National Research Council, “Safety Evaluation Report to Amendment No. 127 to Facility Operating Licence No. DRP-48,” Zion Nuclear Power Station, Unit 2, Washington DC, 1992.
 C. A. Seybold, M. J. Mausbach, D. L. Karlen and H. H. Rogers, “Quantification of Soil Quality,” In: R. Lal, J. M. Kimble, R. F. Follett and B. A. Stewart, Eds., Soil Processes and the Carbon Cycle, CRC Press, Boca Raton, 1998, pp. 387-404.
 G. Miller, “The Whitehorse Initiative: A Case Study in Partnerships, in Management of Commodity Resources in the Context of Sustainable Development: Social Impact of Mining,” Proceedings of United Nations Conference on Trade and Development (UNTAD/ITCD/COMS), Geneva, 1996, pp. 72-81.
 A. Clewell and J. P. Rieger, “What Practitioners Need from Restoration Ecologist,” Restoration Ecology, Vol. 5, No. 4, 1997, pp. 350-354.
 L. D. Karlen and D. E. Stott, “A Framework for Evaluating Physical and Chemical Indicators of Soil Quality,” In: J. W. Doran, D. C. Coleman, D. F. Bezdicek and B. A. Stewart, Eds., Defining Soil Quality for a Sustainable Environment, Special Publication No. 35, Soil Science Society of America, Madison, 1994, pp. 53-72.
 M. J. Haigh, “Degradation of Reclaimed Lands Previously Disturbed by Coal Mining in Wales: Causes and Remedies,” Land Degradation & Development, Vol. 3, No. 3, 1992, pp. 169-180. doi:10.1002/ldr.3400030306
 J. C. Chambers and G. L. Wade, “Evaluating Reclamation Success: The Ecological Considerations,” Proceedings of a Symposium, USDA Forest Service, Northern Forest Experiment Station, Radnor, 1992, p.107.
 J. W. Doran and T. B. Parkin, “Quantitative Indicators of Soil Quality: A Minimum Data Set,” In: J. W. Doran and A. J. Jones, Eds., Methods for Assessing Soil Quality, Special Publication No. 49, Soil Science Society of America, Madison, 1996, pp. 25-37.
 J. Glover, J. Reganold and P. Andrews, “Systematic Methods for Rating Soil Quality of Conventional, Organic and Integrated Apple Orchards in Washington State,” Agriculture, Ecosystems & Environment, Vol. 88, No. 1-2, 2000, pp. 29-45. doi:10.1016/S0167-8809(00)00131-6
 M. C. Amacher, K. P. O’Neil and C. H. Perry, “Soil Vital Signs: A New Soil Quality Index (SQI) for Assessing Forest Soil Health,” Research Paper RMRS-RP-65WWW, Forest Service, Rocky Mountain Research Station, Fort Collins, 2007.
 C. J. Taylor, “The Vegetation Zones of the Gold Coast,” Department Bulletin No. 4, Government Printer, Accra, 1952.
 P. R. Day, “Particle and Particle Size Analysis,” In: C. A. Black, Ed., Methods of Soil Analysis, Part I, Agronomy, American Society of Agronomy, Madison, 1965, pp. 545- 567.
 G. R. Blake and K. H. Hartge, “Bulk Density,” In: A. Klute, Ed., Methods of Soil Analysis, Part 1—Physical and Mineralogical Methods, 2nd Edition, ASA-SSA, Madison, 1986, pp. 363-382.
 W. D. Kemper and R. C. Rosenau, “Aggregate Stability and Size Distribution,” In: A. Klute, Ed., Methods of Soil Analysis, Part 1—Physical and Mineralogical Methods, 2nd Edition, ASA-SSA, Madison, 1986, pp. 425-442.
 D. Hillel, “Introduction to Environmental Physics,” Elsevier Academic Press, Amsterdam, 2004.
 R. H. Bray and L. T. Kurtz, “Determination of Total Organic and Available Forms of Phosphorus in Soils,” Soil Science, Vol. 59, No. 1, 1945, pp. 39-45.
 G. W. Thomas, “Extractable Cations,” In: A. L. Page, R. H. Miller and D. Keeney, Eds., Methods of Soil Analysis, Part 2—Chemical and Biochemical Methods, 2nd Edition, ASA-SSA, Madison, 1982, pp. 159-165.
 G. N. N. Dowuona, I. A. Taina and R. J. Heck, “Porosity Analysis of Two Acrisols by X-Ray Computed Microtomography, Soil Science, Vol. 174, No. 11, 2009, pp. 583- 893. doi:10.1097/SS.0b013e3181c2a90b
 R. F. Sutton, “Soil Properties and Root Development in Forest Trees: A Review,” Forestry Canada Information Report O-X-413, Ottawa, 1991.
 R. F. Fisher and D. Binkley, “Ecology and Management of Forest Soils,” 3rd Edition, John Wiley & Sons, New York, 2000.
 R. F. Harris, G. Chester and O. N. Allen, “Dynamics of Soil Aggregation,” Advances in Agronomy, Vol. 18, 1965, pp. 107-160. doi:10.1016/S0065-2113(08)60649-5
 P. Lavelle, “Earthworm Activities and the Soil System,” Biology and Fertility of Soils, Vol. 6, No. 3, 1988, pp. 237-251. doi:10.1007/BF00260820
 G. N. N. Dowuona, A. R. Mermut, S. G. K. Adiku, E. Nartey and I. Tete-Mensah, “Improvement in the Quality of Soils under Agroforestry Practice in Ghana,” In: G. Renard, A. Neef, K. Becker and M. von Oppen, Eds., Soil Fertility Management in West Africa Land Use Systems, Margraf Verlag, Weikersheim, 1998, pp. 251-258.
 L. P. Wilding and L. R. Drees, “Spatial Variability and Pedology,” In: L. P. Wilding, N. E. Smeck and G. F. Hall, Eds., Pedogenesis and Soil Taxonomy I: Concepts and Interactions, Elsevier, Amsterdam, 1985, pp. 83-116.
 A. O. Ogunkunle and O. O. Eghaghara, “Influence of Land Use on Soil Properties in a Forest Region of Southern Nigeria,” Soil Use Management, Vol. 8, No. 3, 1992, pp. 121-125. doi:10.1111/j.1475-2743.1992.tb00906.x
 G. S. Henderson, “Soil Organic Matter: A Link between Forest Management and Productivity,” In: W. H. McFee and J. M. Kelly, Eds., Carbon Forms and Functions in Forest Soils, Soil Science Society of America, Madison, 1995, pp. 419-435.
 W. H. Schlesinger, “Biogeochemistry: An Analysis of Global Change,” 2nd Edition, Academic Press, San Diego, 1997.
 M. Roberts, The Ground: Interface in the Environment, Resource for Development,” Dunod/Masson, Paris, 1996.
 P. M. Ahn, “Soils of the Lower Tano Basin, Southwestern Ghana,” Memoir No. 1, Department of Soil and Landuse Survey, Kumasi, 1961.