Effects of soil properties on phosphate sorption

Abstract

Abstract Several factors affect phosphate sorption by soils. This study was conducted to evaluate the effects of the chemical and physical properties of surface and subsurface soils of a temperate region on P sorption from solutions containing various concentrations of P. Results showed that Na2S2O4‐extractable Fe and Al of surface soils were significantly correlated with P sorption from a solution containing 10, 15, or 20 ppm P. The relationships between the amounts of P sorbed and the other properties of the surface and subsurface soils studied (e.g., pH, organic C, soluble P, CEC) were influenced by use of 0.01M CaCl2 as an equilibrating solution. The values of P adsorption maxima calculated from soil‐water systems were from 1.2‐ to 2.1‐fold higher than those calculated from soil‐0.01M CaCl2 systems. But the Langmuir adsorption constants calculated from results obtained in the presence of CaCl2 were from 7‐ to 27‐fold higher than those in the absence of salt.