Sulfur (S) is one of the essential nutrients required for plant growth. In recent years, sulfur deficiencies have become more frequent and the importance of sulfur in crop production is becoming more and more recognized. Most of the agricultural soils in arid and semi-arid regions of the world are calcareous soils and S deficiency is a very common phenomenon. Decreasing soil pH is considered, as an effective way to deal with the stabilization of nutrients in calcareous and alkaline soils. Application of sulfur in the soil and its oxidization to sulfuric acid by sulfur-oxidizing bacteria appeared to be a feasible approach for soil pH amendment and subsequently enhancing nutrient availability for plants. The sulfur-oxidizing bacteria naturally exist in the soil however, their population and activity have been significantly limited due to the low levels of organic matter in agricultural soils. This product is developed using potent and exclusive active species of Thiobacillus sp. with high sulfur-oxidizing activity. This product enhances and speeds up the oxidation and conversion of elemental sulfur into sulfuric acid.