Relative Suitability Evaluation of Two Methods of Particle-Size Analysis for Selected Soils of Sudan Savanna of Nigeria
The two widely used methods base on the sedimentation principle (Bouyoucos hydrometer and International pipette) for particle-size analysis were comparatively evaluated on soils collected from various locations in Sudan savanna of Nigeria particularly from Sokoto and Zamfara States. The hydrometer method under-estimated the silt and over-estimated the clay content. Also, the hydrometer reading proved difficult and tended to submerge when floated for clay reading in the suspension of very sandy soils (900g kg-1 sand). Furthermore, the results from the two methods were validated by subjecting the data to USDA soil textural triangle to determine their textural class names. The outcome was that 91.67 % of the experimental soils retained the same textural class names irrespective of the method. Thus, Bouyoucos hydrometer method may conveniently find a place in routine work in view of its simplicity, rapidity, and strong correlation with the pipette method.
 N.C. Brady and R. Weil, 2010. Elements of the Nature and Properties of Soils. 3rd edition. Pearson Education, Inc., Upper Saddle River, New Jersey 07458. 163pp.
 FAO, 2006. "Plant nutrition for food security. A guide for integrated nutrient management”. R.N. Roy, A. Finck, G.J. Blair and H.L.S. Tandon (eds.). FAO Fertilizer and Plant Nutrition Bulletin 16. Food and Agricultural Organization of the United Nations, Rome. 348pp.
 FAO. 2005. "The importance of soil organic matter: Key to drought-resistant soil and sustained food and production”. A. Bot and J. Benites (eds). FAO Soil Bulletin 80. Food and Agricultural Organization of the United Nations, Rome. 78pp.
 J.M. Singer and N. Munns, 1999. Soils: An introduction. Fourth edition. New Jersey. Prentice Hall Inc. 527pp.
 T.A. Kettler, J.W. Doran and T.L. Gilbert, 2001. Simplifed Method for Soil Particle-Size Determination to Accompany Soil-Quality Analyses. Soil Sci. Soc. Am. J. 65:849–852.
 ISRIC/FAO, 2002. "Procedures for Soil Analysis”. Sixth edition L.P. van Reeuwijk (ed.). International Soil Reference and Information Centre/Food and Agricultural Organisation. 119pp.
 R.B. Brown, 1990. Soil texture. Fact Sheet SL-29, Soil and Water Science Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, USA. 8pp.
 G.W. Gee and J.W. Bauder. 1986. "Particle-size analysis”. In A. Klute (ed.) Methods of soil analysis. Part 1. 2nd ed. Agron. Monogr. 9. Am. Soc. Agron. and Soil Sci.Soc.Am, Madison, WI. pp 383–411.
 B.H. Sheldrick and C. Wang, 1993. "Particle Size Distribution”. In MR Carter (ed.) Soil Sampling and Methods of Analysis. Canadian Society of Soil Science. Lewis Publishers. Ann Arbor. pp. 499-511.
 L. Beuselinck, G. Govers, J. Poesen, G. Degraer and L. Froyen, 1998. Grain-size analysis by laser diffractometry: comparison with the sieve-pipette method. Catena 32:193-208.
 A.A. Abdullahi, S.A. Ibrahim, T.I. Garba, S.S. Noma, M. Audu and H. Shuaibu, 2010. Influence of Vegetation on Soil Fertility in Zamfara Grazing Reserve, Sudan Savanna Zone, Nigeria. In L.B. Taiwo, G.A. Oluwatosin, J.A Adediran, K.S. Are, A.O. Oke and S.O.Ojeniyi (eds.). Proceedings of the 34th Annual Conference of the Soil Science Society of Nigeria. Institute of Agricultural Research and Training, Moor Plantation, Ibadan, Nigeria. pp 115-123.
 S.S. Noma, P.T. Obianyor, M. Yakubu, M. Audu, A.A. Abdullahi, A.U. Dikko and N.M. Danmowa, 2010. Soil Colour as a pedo-transfer function of some soils in Sokoto, semi-arid, Nigeria. In L.B. Taiwo, G.A. Oluwatosin, J.A Adediran, K.S. Are, A.O. Oke and S.O.Ojeniyi (eds.). Proceedings of the 34th Annual Conference of the Soil Science Society of Nigeria. Institute of Agricultural Research and Training, Moor Plantation, Ibadan, Nigeria. pp 86-93.
 A. Faniran and O. Areola, 1978. Essentials of Soil Study. Heinemann Educational Books, London. pp 246-252.