Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 Maize response to sulfur and thiobacillus inoculation in calcareous soils 17 22 3731 10.47176/dlsr.02.01.1025 EN Hosein Besharati Soil and Water Research Institute, Agricultural Research, Education and Extension Organizatio, Karaj, Iran Mahmoud Solhi Agricultural Research Center, Agricultural Research, Education and Extension Organizatio, Isfahan, Iran Abdolhossein Ziaeian Agricultural Research Center, Agricultural Research, Education and Extension Organizatio, Kerman, Iran Arash Sabbah Agricultural Research Center, Agricultural Research, Education and Extension Organizatio, Kerman, Iran Journal Article 2023 11 11 Calcareous soils are widely distributed in the arid and semi-arid regions, where most agricultural soils in Iran, due to climatic conditions and geological formations, are calcareous and have a high pH. In such soils, some nutrients like phosphorus, are fixed and utilizing acid-forming substances  may increase the availability of this element.  Sulfur is considered to be the most affordable acid-producing material and is a byproduct of gas and oil refineries with an annual production of more than two million tons in Iran. In this research, the effects of bentonite-sulfur produced by a new process were tested on maize silage (Single Cross 704 cultivar) on agricultural soil research farms at three sites (Isfahan, Shiraz, and Jiroft) using  a factorial experiment. For this purpose, 0, 0.5, 1, and 2 t ha^-1 of the elemental sulfur as well as 0, 65, and 100% of recommended phosphorus  were applied. Application of elemental sulfur was combined with the inoculation of Thiobacillus bacteria (1 kg per 50 kg of elemental sulfur). Results indicated that sulfur, phosphorus, and their co-application brought about significant increases in maize shoot dry and fresh weights only at Shiraz site. Sulfur application enhanced the shoot uptakes of zinc and iron at Shiraz and Jiroft sites. The highest Fe uptake was observed with application of 2,000 kg ha^-1 of sulfur. No significant effects were, however, detected on shoot phosphorus uptake at any of the study sites. Elemental sulfur was observed to have a limited effect on soil nutrient availability and plant growth because of the high buffering capacity of the studied sites calcareous soils, counteracting the acidification of sulfur oxidation. https://dlsr.iut.ac.ir/article_3731_7ec3b3cf674f4f1d23e9d30c89426cce.pdf