Solubility of simple aluminium compounds expected in soils. III. Aluminium ions in soil solutions and aluminium phosphates in soils

Abstract

Many published values for the aluminium contents of displaced solutions and extracts from soils at varying pH values have been examined and found to be quite compatible with recent findings that A1OH2+, Al(OH)2+, or their polymers are dissolution products from aluminium hydroxide. Variation of phosphate content has also been considered and no case can be made for the presence of variscite in the systems examined. As far as aluminium compounds are concerned, the evidence is in favour of sorption of phosphate by the aluminium oxyhydroxide surfaces in the soil.