effect of converter sludge and slag of isfahan iron melting factory on corn yield and some heavy metal uptake in a calcareous soil

many researchers have reported positive effects of converter sludge and slag, two by-products in isfahan iron melting factory. in this work, the optimum rate of application and the availability of some essential elements (for plant growth) in the converter sludge and slag for corn were investigated. the converter sludge contains about 64% fe іі and ііі oxides and some other essential elements for plant growth. the slag also contains 17% iron oxides, 52.8% calcium oxide as well as considerable amounts of some other elements. treatments included a control, fe-edta foliar spray with 5 in 1000 concentration, application of sludge in 4 levels (l1, l2, l3 and l4 equal to 5.83, 13.33, 20.83 and 26.67 ton/ha, respectively) and application of slag in 4 levels (s1, s2, s3 and s4 equal to 3.20, 7.28, 11.36 and 15.44 ton/ha, respectively) which supply 1, 2, 3 and 4 times as much as soil test recommends, based on ab-dtpa extractable fe in the soil. corn (zea mays) single cross 704 was planted for the experiment. applications of the two compounds increased the soil extractable fe and mn, decreased mg but the treatment did not change the soil-extractable zn, cu and ca. the corn yield also increased due to the applications of the two compounds and the maximum yield was related to l3, l4, s3 and s4 treatments. the foliar application treated the leaf chlorosis and increased the silage, grain and leaf + stalk yields however, this was not as efficient as sludge and slag application. also applications of the two compounds increased the fe, mn, zn, cu, ca and mg uptake by corn. the l3 and s3 treatments can be recommended as the proper levels of these compounds as iron fertilizer.