Research on aluminium speciation in poor forest soils using the sequential extraction method

Research on aluminium speciation was performed using a slightly modified version of Tessier’s procedure. The soils under study displayed strongly acidic character (pH KCl of 3.3 - 4.4). The content of aluminium in the exchangeable (11 mg/kg), acid extractable (67 mg/kg), oxidizable (2650 mg/kg), reducible (658 mg/kg) and residual fraction (24,680 mg/kg) varied widely. The percentage of labile phase (sum minus residual) obtained for mean values in the profile amounted to 12.1%, which may indicate its considerable bioavailability. The soil profile under study displayed a lithogenically dichotomous structure, which was also reflected in the aluminium content in the particular fractions.