Phosphorus sorption properties in podzolic forest soils and soil solution phosphorus concentration in undisturbed and disturbed soil profiles

Podzol horizons (O, E, B 1, 132 and C) from three undisturbed sites were analyzed for phosphorus (P) sorption, P saturation, P fractions, and P concentrations in soil solutions, and three disturbed Podzols for P in soil solution. The threshold concentrations for net sorption were 8000 mu g 1(-1) and 700 mu g 1(-1) for the O and E horizons, respectively, and 3-6 mu g 1(-1) for the B1, B2 and C horizons. Consequently, if water percolates through the B horizon the risk of P leaching is low. Phosphorus saturation degree was 0.2%-25%. Fe-P dominated in the O, E, B1 and B2 horizons, and Ca-P in the C horizon. P was depleted from the E horizon (24 mu g g(-1)) and enriched in the B1 and B2 horizons (500 and 250 mu g g(-1)) as compared with that in the C horizon (160 mu g g(-1)). P in soil solution increased in the topmost 3 cm of the disturbed B horizons.