Indian Journal of Agricultural Research

Phosphorus adsorption-desorption behaviour of soils under four land use patterns viz, forest, orchard, cultivated land and tea garden of terai agro climatic region were studied. Phosphorus adsorbed at 0.2 mg L⁻¹ equilibrium solution P concentration in these land uses was low (40.2 to 67.6 mg kg⁻¹). The adsorption behaviour of these soils could significantly be by Freundlich, modified Freundlich, Langmuir and Tempkin equations. Phosphorus adsorption at 0.2 mg L⁻¹ equilibrium solution P concentration significantly correlated with organic carbon (r = 0.520**), CEC(r = 0.414**), free Fe₂O₃ (r = 0.385**) and AEC (r = 0.255*), suggesting the role of these soil characteristics in P sorption process. A substantial amount (32.2 to 52.2%) of added P was extracted during two successive desorption with 0.5 M NaHCO₃ (pH 8.5).