Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2001.1460.1465J. Nouri B. J. Alloway P.J. Peterson 122001412A number of extractions were carried out on soils, in order to assess both the relative concentrations of metals available to plants and also the major forms in which these metals existed in soils. The objective of this study was to assess the quantity and forms of metals in different soils, sludge and soils amended with sludge. It seemed that initially each metal will respond differently after incorporation into the soil system. There was a greater fraction of soluble metals in the sludge amended soils than the controls. Micro-organisms might, by using organic and inorganic matter as source of carbon and energy, bring about oxidation and reduction sufficient to change the state of metals.]]>Bradford, G.R., A.L. Page, L.J. Lund and W. Olmstead, 19754123127Alloway, B.J.,19951995Mclaren, R.G. and P.V. Crawford, 197324172181Martell, A.E. and M. Calvin, 1952Alloway, B.J. and A.P. Jackson, 1991100151176Lindsay, W.L. and W.A. Norvell,19692+, Fe3+, Ca2+ and H+ with EDTA and DTPA in soils.]]>336268Lindsay, W.L. and W.A. Norvell, 19691969Bloomfield, C. and G. Pruden, 19758217232Page, A.L., 1974Berrow, M.L. and J. Webber, 19722393100Andersson, A. and K.O. Nilsson, 197431982000Alloway, B.J., M.L. Gregson, S.K. Gregson, R. Tanner and A. Tills,19791979pp: 545548Chumbley, C.G., 19711971Sorensen, R.C., D.D. Oelsligle and D. Knudsen, 1971111352359Lagerwerff, J.V., D.L. Brower and G.T. Giersdorf, 19731973Warren, H.V. and R.E. Delavault, 196069495504Nouri, J.,19801980Essington, M.E. and S.V. Mattigod, 199155350356Stover, R.C., L.E. Sommers and D.J. Silviera, 19764821652175Brallier, S., R.B. Harrison, C.L. Henry and X. Dongsen, 19968614Juste, C. and P. Solda, 19773147155Keefer, R.F. and R.N. Singh, 19861422026Silviera, D.J. and L.E. Sommers, 197764752Pavoni, J.L.,19701970