Effect of several organic acids on phosphate adsorption by variable charge soils of central China

Abstract

The effect of several organic acids on phosphate adsorption by acidic soils in subtropical zone of central China was studied. Results showed: (1) citrate and oxalate remarkably reduced the amount of phosphate adsorption, but tartrate, benzoate and acetate had only a very slight influence on phosphate adsorption; (2) the ability of citrate in reducing phosphate adsorption was greater than that of oxalate, moreover, the reduction percentage was dependent on the concentration of organic ligands in the solution; (3) the effect of organic acids on phosphate adsorption was related to the pH value of organic acid solution. The minimum reduction in adsorption of phosphate was present at a specific p..