حسین بشارتی
آرش صباح
ناصر رشیدی
حمیدرضا ذبیحی
عبدالحسین ضیائیان
جلال قادری
مهرزاد مستشاری
کامران میرزاشاهی
محمود صالحی

Elemental sulfur is a byproduct of gas and petroleum refineries, which annually is produced over two million tons in the country. In order to Feasibility study of sulfur application in agricultural soils, Sulfur-bentonite which formulated by Institute of Petroleum Industry, was evaluated in corn cultivated soils in 8 regions in, Kermanshah, Khuzestan, Fars, Isfahan, Khorasan, Qazvin and Kerman(and Jiroft) provinces. Treatments included different levels of sulfur (control, 500, 1000 and 2000 kg So per hectare) and triple super phosphate levels (control, 65 and 100 per cent phosphorus recommended based on soil test). The results of compound analysis of 8 mentioned regions indicated that the effect of sulfur, phosphorus, location as well as their interactions on corn dry and wet yield were significant. Sulfur levels increased significantly corn wet and dry yield compared with the control, the rates of 1 and 2 tons of sulfur application were not different significantly, but they had significat difference with the 0.5 ton rate. Also, the three rates of sulfur (0.5, 1 and 2 ton) significantly increased the iron uptake of corn compared to control, and no significant difference was between 5.0 and 1 tons, while the 2 ton rate had the highest iron uptake and its difference with other treatments were significant. No sulfur application rates had significant effect on plant zinc and phosphorus content. Also sulfur rates had no significant impact on chemical properties of soil compared to the control. Only application of 2 tons of sulfur per hectare significantly increased soil salinity (EC) compared to the control. According to the results, and also taking into account the economic aspect of sulfur usage, about one ton of elemental sulfur in corn cultivated soils is recommendable. . Keywords: Sulfur-bentonite, Thiobacillus, Corn, Soil test, Calcareous soil, Available-P.