Abstract: The total removed radio-iodine in surface layer of the soil demands some factors. These factors consist of detention time of animal fertilizer in the soil, amount of animal fertilizer given to soil and depth of used animal fertilizer in the soil in which were unknown and so they were determined. In the lab an experimental system reproducing the environmental conditions of the contaminated areas were designed in pots and Radio polluted sub samples soil was treated with old feces of sheep and cow which are normally used as common fertilizers. Seven days from the contamination of sub soil samples treated with animal feces as fertilizers present at the time of inoculation, a drop up to 53%, with 1/4 volume of animal fertilizer: 3/4 volume of sub sample soil in radioactivity rate was indicated, after a series of washes which simulate one year`s rainfall. Radio iodine movement towards deeper soil layers, following old animal fertilizer treatments and their subsequent stabilization reduces bioavailability in the uppermost soil horizon.