organic acids exuded by plant roots increase solubility of soil micronutrient complexes. this study was carried out to evaluate adsorption isotherms of 4 acidic and 4 calcareous soils at presence of organic acids (citric, malic and oxalic acids). iron sorption and desorption isotherms are defined in to two systems including; system 1; soil-water-metal, system 2; soil-water-organic acid-metal). ...