01355naa a2200217 a 450000100080000000500110000800800410001910000230006024501180008326000090020152007690021065000090097965000130098865000170100165000090101865300190102765300180104665300130106470000180107777300420109513658552012-02-16       1969    bl ---       0--  u    #d1 aWILLIAMS, T. D. H.  aFractionation of phosphate in a maturity sequence of New Zealand basaltic soil profilesbIh[electronic resource]  c1969  aChang and Jackson (6) stated that the transformations of inorganic phosphate during soil weathering followed the sequence: calcium phosphate, aluminum phosphate, iron phosphate, occluded phosphate. In proposing this theory they took the view that aluminum and iron bound phosphate in soils was predominantly in the form of discrete crystalline phases such as variscite, strengite, etc. This view, referred to here as the "discrete phosphate" theory, has often been questioned, for example in recent papers by Bache (1,2), Bauwin and Tyner (3), Hsu (11) and Raupach (18). The Alternative theory, called here the "dispersed phosphate" theory, regards iron and aluminum bound phosphate in soils as consisting of phosphate ions chemisorbed on the surfaces or occluded.  asoil  aFósforo  aLevantamento  aSolo  aFertilização  aNova Zelandia  aProfiles1 aWALKER, T. W.  tSoil Sciencegv. 107, p. 22-30, 1969.