Iron oxihydroxides form strong chemical bonds with phosphate anions, reducing P availability to plants. The objective of this study, conducted in 1994/95, was to quantify forms of iron oxides in soils from Uruguay, and to study their relationships with phosphorus sorption. Iron oxides extracted with dithionite-citrate-bicarbonate (Fed) from ten soil samples (0-15 cm depth) ranged from 1598 to 8.592 mg kg-1 and were related with their parent material. Poorly ordered Fe-oxihydroxides, extracted by 0.2 mol L-1 ammonium oxalate at pH […]