ABSTRACT Three land use types (natural fallow, Leucaena leucocephala woodlot and cultivated plots) on a Ferric Acrisol in a semi-arid tropical zone of Ghana were compared to assess their effects on variability in selected soil properties and plant biomass accumulation. Organic carbon accumulation in the representative natural fallow profile was 22.7 g/kg, followed by 16.5 g/kg for the Leucaena woodlot and lastly 11.8 g/kg for the cultivated site. The mean bulk density of the natural fallow, Leucaena woodlot and cultivated sites were from 1.36 Mg/m3, 0.92 Mg/m3 and 1.33 Mg/m3 with corresponding range in mean weight diameter of 0.5 mm - 1.2 mm, 0.6 mm - 1.2 mm and 1.0 mm - 1.2 mm, respectively. The lower bulk density observed for the woodlot corresponds to increased total porosity, aeration, and root proliferation due to the stronger and extensive rooting system. Significant differences (P < 0.05) in bulk density, mean weight diameter (MWD), clay content, organic carbon and total nitrogen existed among the land use types. Variability in pH and bulk density of the surface soils was less than 15%, in the three land use types. Generally, clay content and exchangeable Na recorded the highest variability (>36%). For the surface soils, exchangeable Na was very variable in the natural fallow. Exchangeable Na, Ca and K and total nitrogen were very variable in the Leucaena woodlot and the cultivated sites. Variability in clay content was very high in the cultivated soils only. The order cultivated land > Leucaena woodlot > natural fallow was noted for properties with high variability (CV > 36%). Plant biomass accumulation was 1834 kg/ha (natural fallow) and 830 kg/ha (Leucaena woodlot) indicating that natural fallows do not only maintain soil quality but they also decrease variability in soil properties which is desirable for soil productivity and quality.
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E. Ghartey, G. Dowuona, E. Nartey, T. Adjadeh and I. Lawson, "Assessment of Variability in the Quality of an Acrisol under Different Land Use Systems in Ghana," Open Journal of Soil Science, Vol. 2 No. 1, 2012, pp. 33-43. doi: 10.4236/ojss.2012.21006.
 P. Goovaerts, “Geostatistical Tools for Characterizing the Spatial Variability of Microbiological and Physico-Chemical Soil Properties,” Biology Fertilizers and Soil, Vol. 27, No. 4, 1998, pp. 315-334. doi:10.1007/s003740050439
 A. A. Amusan, A. K. Shitu, W. O. Makinde and O. Orewole, “Assessment of Changes in Selected Soil Properties under Different Land Use in Obafemi Awolowo University Community, Ile-Ife, Nigeria,” Electronic Journal of Environmental Agriculture, Food Chemistry, Vol. 5, No. 1, 2006, pp. 1178-1184.
 W. E. Larson and F. J. Pierce, “The Dynamics of Soil Quality as a Measure of Sustainable Management,” In: J. W. Doran, D. C. Coleman, D. F. Bezdicek and B. A. Stewart, Eds., Defining Soil Quality for a Sustainable Environment, Soil Science Society of America Special Publication, Madison, 1994, pp. 37-70.
 G. N. N. Dowuona, I. A. Taina and R. J. Heck, “Porosity Analysis of Two Acrisols by X-Ray Computed Microto-mography,” Soil Science, Vol. 174, No. 11, 2009, pp. 583- 893. doi:10.1097/SS.0b013e3181c2a90b
 B. T. Kang, “Alley Cropping: Past Achievements and Future Directions,” Agroforestry Systems, Vol. 23, No. 2-3, 1993, pp. 141-155. doi:10.1007/BF00704912
 C. M. A. Smaling, L. O. Fresco and A. de Jager, “Classifying. Monitoring and Improving Nutrient Stocks and Flows in African Agriculture,” AMBIO, Vol. 25, No. 8, 1996, pp. 492-496.
 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.
 D. E. Mercer and S. Pattanayak, “Agroforestry Adoption by Small Holders,” In: Sills E. and K. Abt, Eds., Forests in a Market Economy, Kluwer, Dordrecht, 2003, pp. 283- 300.
 D. E. Mercer, “Adoption of Agroforestry Innovations in the Tropics: A Review,” Agroforestry Systems, Vol. 61- 62, No. 1-3, 2004, pp. 311-328.
 P. H. Nye and D. Stephens, “Soil Fertility,” In: J. B. Wills, Ed., Agriculture and Land Use in Ghana, Oxford University Press, London, 1962, pp. 127-143.
 R. Lal, “Soil Carbon Sequestration to Mitigate Climate Change,” Geoderma, Vol. 123, No. 1-2, 2004, pp. 1-22.
 A. D. Arowolo, “Alley Farming and Sustainable Agriculture” Proceedings of Annual Conference of IRDI Re- search and Development Network, Vol. 2, No. 4, 2007, pp. 27-28, 44-48.
 A. B. McBratney and M. J. Pringle, “Estimating Average and Proportional Variograms of Soil Properties and their Potential Use in Precision Agriculture,” Precision Agriculture, Vol. 1, No. 2, 1999, pp. 125-152.
 A. Castrignano, M. Mazzoncini and L. Giugliarini “Spatial Characterization of Soil Properties,” Advances in GeoEcology, Vol. 31, 2002, pp. 105-111.
 Y. Jafar, S. Mahboub, F. Hamed, K. Najafali, E. Mostafa and B. Majid, “Spatial Variability of Soil Fertility Properties for Precision Agriculture in Southern Iran,” Journal of Applied Sciences, Vol. 8, No. 9, 2008, pp. 1642-1650.
 G. N. N. Dowuona, L. Atsivor and S. G. K. Adiku, “A Multi-Criteria Evaluation of Three Land Use Systems in Ghana,” In: G. Renard, S. Krieg, P. Lawrence and M. Von Oppen, Eds., Farmers and Scientists in a Changing Environment: Assessing Research in West Africa, Margraf Verlag, Weikersheim, 2000, pp. 157-162.
 H. Brammer, “Soils,” In: J. B. Wills, Ed., Agriculture and Land Use in Ghana, Oxford University Press, London, 1962, pp. 88-126.
 P. R. Day, “Particle and Particle Size Analysis,” In: C. A. Black, Ed., Methods of Soil Analysis, Agronomy No. 9, Part I, 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, American Society of Agronomy- Soil Science Society of America, 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, American Society of Agronomy-Soil Science Society of America, Madison, 1986, pp. 425-442.
 D. Hillel, “Introduction to Environmental Physics,” Elsevier Academic Press, Amsterdam, 2004.
 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, American Society of Agronomy-Soil Science Society of America, Madison, 1982, pp. 159-165.
 J. M. Bremner and C. S. Mulvaney, “Nitrogen—Total”, In: A. L. Page, R. H. Miller and D. Keeney, Eds., Methods of Soil Analysis, Part 2—Chemical and Biochemical Methods, American Society of Agronomy-Soil Science Society of America, Madison, 1982, pp. 595-622.
 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. 39-46.
 H. Tiessen, M. K. Abekoe, L. H. Salcedo and E. Owusu-Bennoah, “Reversibility of Phosphate Sorption by Ferruginous Nodules,” Plant and Soil, Vol. 153, No. 1, 1993, pp. 113-124. doi:10.1007/BF00010550
 P. M. Huang, “Ionic Factors Affecting Aluminum Transformations and the Impact on Soil and Environmental Sciences,” University of Saskatchewan, Saskatoon, 1988.
 G. N. N. Dowuona, “Correlation of the Ghanaian System of Soil Classification with other International Systems,” Master’s Thesis, University of Ghana, Legon, 1985.
 P. N. Eze, “Characterization, Classification and Pedogenesis of Soils on a Legon Catena in the Accra Plains, Ghana,” Master’s Thesis, University of Ghana, Legon, 2008.
 V. M. Dang and D. W. Anderson, “Application of Soil Taxonomy Classification to Northern Vietnam,” Vietnamese Soil Science, Vol. 13, 2000, pp. 15-23.
 N. C. Brady and R. R. Weil, “The Nature and Property of Soils,” 12th Edition, Prentice-Hall Inc., New Jersey, 1999.
 T. N. Chaudhary and K. S. Sandhu, “Soil Physical Environment and Root Growth,” Advances in Soil Science, Vol. 1, 1983, pp. 1-43.
 K. H. Tan, “Principles of Soil Chemistry,” Marcel Dekker Inc., New York, 1982.
 A. Yifru and B. Taye, “Effects of Landuse on Soil Organic Carbon and Nitrogen in Soil of Bale, Southeastern Ethiopia,” Tropical and Subtropical Agroecosystems, Vol. 14, No. 1, 2011, 229-235.
 F. Caravaca, G. Masciandaro, and B. Ceccanti, “Land Use in Relation to Soil Chemical and Biochemical Properties in a Semiarid Mediterranean Environment,” Soil and Tillage Research, Vol. 68, No. 1, 2002, pp. 23-30.
 D. D. Malo, T. E. Schumacher and J. J. Doolittle, “Long- Term Cultivation Impacts on Selected Soil Properties in the Northern Great Plains,” Soil and Tillage Research, Vol. 81, No. 2, 2005, pp. 277-291.
 G. Heluf and N. Wakene, “Impact of Land Use and Man- agement Practices on Chemical and Properties of Some Soils of Bako Area, Western Ethiopia,” Ethiopian Journal of Natural Resources, Vol. 8, No. 2, 2006, pp. 177-197.
 G. Guggenberger, W. Zech and R. J. Thomas, “Lignin and Carbohydrate Alteration in Particle Size Separates of an Oxisol under Tropical Pastures Following Native Savanna,” Soil Biology and Biochemistry, Vol. 27, No. 12, 1995, pp. 1629-1638.
 H. T. Riezebos and A. C. Loerts, “Influence of Land Use Change and Tillage Practices on Soil Organic Matter in Southern Brazil and Eastern Paraguay,” Soil and Tillage Research, Vol. 49, No. 3, 1998, pp. 271-275.
 R. G. Barber, “Soil Degradation in Tropical Low Lands of Santa Cruz, Eastern Bolivia,” Land Degradation and Rehabilitation, Vol. 6, No. 2, 1995, pp. 95-107.
 J. H. Patrick and D. W Smith, “Forest Management and Nutrient Cycling in Eastern Hardwoods,” Northeast Forestry Experimental Station, Broomall, 1975.
 G. D. Mroz, M. F. Jurgensen and D. J. Frederick, “Soil Nutrient Changes following Whole Tree Harvesting on Three-Northern Hardwood Sites,” Soil Science Society of America Journal, Vol. 49, No. 6, 1985, pp. 1552-1557.
 J. Six, E. T. Elliott and K. Paustian, “Aggregate and Soil Organic Matter Dynamics under Conventional and No-Tillage Systems,” Soil Science Society of America Journal, Vol. 63, No. 5, 1999, pp. 1350-1358.
 I. Celik, “Land-Use Effects on Organic Matter and Physical Properties of Soil in a Southern Mediterranean High- land of Turkey,” Soil and Tillage Research, Vol, 83, No. 2, 2005, pp. 270-277. doi:10.1016/j.still.2004.08.001
 R. Lal, “Tropical Ecology and Physical Edaphology,” John Wiley & Sons, Chichester, 1987
 C. E. Seubert, P. A. Sanchez and C. Valverde, “Effects of Land Clearing Methods on Soil Properties of an Ultisol and Crop Performance in the Amazon Jungle of Peru,” Tropical Agriculture, Trinidad, Vol. 54, 1977, pp. 307-321.
 J. Allen, “Soil Response to Forest Clearing in the United States and in the Tropics: Geological and Biological Factors,” Biotropica, Vol. 17, No. 1, 1985, pp. 15-27.
 E. J. A. Spaans, G. A. M. Baltissen, J. Bouma, R. Miedema, A. L. E. Lansu, D. Schoonderbeek and W. G. Wielemaker, “Changes in Physical Properties of Young and Old Volcanic Surface Soils in Costa Rica after Clearing of Tropical Rain Forest,” Hydrological Processes, Vol. 3, No. 4, 1989, pp. 383-392. doi:10.1002/hyp.3360030409
 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, 1983, pp. 83-116.