Iron chlorosis in plants, especially fruit trees, is a world wide nutritional problem. It is widespread in all fruit-qrowing regions in Iran. Although synthetic iron chelates can effectively correct the Fe chlorosis, they are too costly to be used economically in vast areas. Organic materials enriched with iron may be an inexpensive and suitable alternative for iron chelates. Thirteen (no 1 to 13) organic iron fertilizers were prepared by mixing organic matter from six sources, iron from three sources and S powder in concrete containers and incubating the mixtures at 25% moisture content and 20-30 C for three months. Effect of these fertilizers on iron chlorosis of soybeans in two soils was investigated in a green house experiment. Fertilizers number 3,6,8,9, and 11 showed good effect, number 1, 2,7 and ‘12 showed medium effect and number 4,5,10 and 13 showed poor effect on correcting iron chlorosis and increasing chlorophyll and iron content of soybean leaves. Ferrous sulfate was the most suitable and a by-product of Isfahan steel factory was the least suitable iron source for enrichment of organic matters
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