The retention of strontium from solutions (concentration range 2 to 30 mg/l) by soils developed under arid conditions of Iran was investigated using a batch technique. Sr sorption characteristics a clayey and a silty clay loam soil were examined at room temperature and with 0.01M CaCl2 as a background electrolyte. Sorption processes are found to show a Freundlich-type behavior. Results indicated the clay content and ionic strength play predominant role on sorption of Sr. At soil with high soluble cations (saline-sodic soil) less strontium was adsorbed at lower concentrations of strontium due to greater competition with other cations especially with soluble Ca and Mg. Electrical conductivity and ratio of soluble Ca and Mg to total soluble cations is important especially in soils with high EC and SAR.
