International Journal of Soil Science1816-4978xxxx-xxxxAcademic Journals Inc.10.3923/ijss.2006.64.74RajiB. A.1200611In the study of pedogenetic processes, knowledge of soil phosphorus transformation can be regarded as a valuable tool. This research was conducted to study the suitability of soil phosphorus as an index of soil weathering in strongly acid soils in the semiarid savanna of Nigeria. Phosphorus fractions from selected modal soil profiles formed on contiguous Tertiary and Quaternary sand dune of a chronosequence that ranges in age from 5,000 to over 100,000 years were studied. Using chemical extraction methods, total phosphorus, organic phosphorus and the various active inorganic phosphorus fractions were determined. The phosphorus fractions showed clear developmental trends in the A horizons than in the subsoils. In the surface horizons, calcium phosphate (Ca-P), and iron phosphates (Fe-P) tended to decrease over time while organically bound phosphorus (Po) and residual phosphorus (residual-P) increased over time. The most prominent features of the P transformation are the loss of about 7650 kg ha-1 m-1 profile of calcium phosphate and 10,100 kg ha-1 m-1 profile of total phosphorus (TP), both in 105 years. Increase in Po was 760 kg ha-1 m-1 profile and that of residual-P was 2,929 kg ha-1 m-1 profile, also in 105 years, thereby, giving a fairly low rate of P transformation. The relative order of P transformation was: Po > residual-P > Ca-P > Fe-P and Al-P. The results of this study showed that factors other than chronological age also influenced the trends. The strongly weathered nature of the parent materials prior to deposition most probably limited the usefulness of P-fractions as an index of soil weathering in the chronosequence and also, most probably, was responsible for the slow rate of P transformation. The results of this study showed that the P fractions in the surface horizons exhibited clearer developmental trends, but in the subsoil the trend was irregular with chronological age.]]>Agbenin, J.O. and H. Tiessen,199462345362Blake, G.R. and K.H. Hartge,19862nd Edn.,pp: 363-375pp: 363-375Buol, S.W., F.D. Hole and R.J. McCracken,19731st Edn.,pp: 278pp: 278Daroub, S.H., B.G. Ellis and G.P. Robertson,200064170176Day, L.D., M.E. Collins and N.E. Washer,19875115471553Heakal, M.S., M.H. Al-Awajy, M.S. Al-Sewailem, F.N. Barakah and A. Al-Asheikh,199546481488Jenny, H.,1941Pages: 281Pages: 281James, M.J. and A. Wild, 197555218218Lekwa, G. and E.P. Whiteside,198650160166Loganathan, P. and P.M. Sutton,19871431625McKeague, J.A. and J.D. Day,1966461332McKeague, J.A., J.E. Brydon and N.M. Miles,1971353338Meixner, R.E. and M.J. Singer,19851393746Moberg, J.P., I.E. Esu and W.B. Malgwi,1991487381Murphy, J. and J.P. Riley,1962273136Raji, B.A., I.E. Esu, V.O. Chude, J.J. Owonubi and T. Kparmwang,199670425432Raji, B.A., I.E. Esu, V.O. Chude and E.Y. Adefila,1996132537Raji, B.A., E.I. Esu and V.O. Chude,199994759Raji, B.A., I.E. Esu and V.O. Chude,2000164151Ridley, J.R.,19841984Runge, E.C.A., T.W. Walker and D.T. Howarth,197447684Smeck, N.E.,198536185199Stevens, P.R. and T.W. Walker,197045333350Tisdale, S.L., W.L. Nelson and J.D. Beaton,1985Udo, E.J. and J.A. Ogunwale,19774111411146Walker, T.W. and J.K. Syers,197615119Washer, N.E. and M.E. Collins,198852191196William, J.D.H., J.K. Syers and T.W. Walker,1967311736739William, J.D.H., J.K. Syers, T.W. Walker and R.W. Rex,19701101318William, J.D.H., T. Mayer and J.O. Nriagu,198044462465Sombroek, W.G. and I.S. Zonneveld,19711971SAS,1998Version 7,Nelson, D.W. and L.E. Sommers,19831983pp: 539-579pp: 539-579Nelson, R.E.,19821982pp: 181-197pp: 181-197Kogbe, C.A.,19792420420