Abstarct: Abstract In Iran, the majority of soils are calcareous, low in organic matter, and their pH typically ranges between 7.5 and 8.5 due to the presence of calcium carbonate and poor irrigation water quality (high concentrations of bicarbonate ions, etc.). As a result, a significant proportion of essential mineral elements for plants, such as phosphorus, iron, zinc, copper, manganese, and others, are immobilized and rendered unavailable. Despite their presence in the soil, plants cannot utilize these elements, creating challenges in crop production. One of the solutions to reduce the use of chemical fertilizers and harness native soil nutrient sources is to lower soil pH through the application of acids and acidifiers in the soil or irrigation water.To investigate the effect of acidified irrigation water, prepared using a sulfur burner device, on soil chemical properties and nutrient absorption by forage corn (Single Cross 704 cultivar), a two-year field study was conducted. In the first year, the experiment was factorial within a randomized complete block design, while in the second year, it followed a split-plot design in a randomized complete block layout with three replications. The study was carried out in the research fields of the Soil and Water Research Institute in Meshkin Dasht, Alborz Province, over two summer cropping seasons from 2021 to 2022.In the first year, only irrigation treatments were applied, while in the second year, irrigation treatments were combined with fertilizer treatments. In the first year, the factors were: (1) type of irrigation water at two levels: (a) conventional irrigation water (pH 7.5–8.5) and (b) acidified irrigation water produced by the sulfur burner (pH 2.0–2.5); and (2) sampling time at two stages: (a) before tasseling and (b) after tasseling. In the second year, the factors were: (1) type of irrigation water at the same levels as in the first year, and (2) chemical fertilizer treatments at five levels: (a) control (no fertilizer), (b) application of urea (N), (c) urea + triple superphosphate (NP), (d) urea + triple superphosphate + iron and zinc fertilizers from sulfate sources (N+P+Fe+Zn(Sulfate)), and (e) urea + triple superphosphate + iron and zinc fertilizers from chelated sources (N+P+Fe+Zn(Chelate)). The first-year results showed that using acidified water led to improvements in growth and yield traits of forage corn, increasing total dry yield by 13.28% and cob dry yield by 20.7%. Soil pH decreased, while EC increased alongside the use of acidified irrigation water. Soluble chloride and bicarbonate in the soil also decreased, whereas soil organic carbon percentage increased. Overall, the acidified water treatment applied after tasseling proved to be the most effective.The second-year results similarly demonstrated that the application of acidified water improved growth and yield traits, increasing total dry yield by 31.14% and cob dry yield by 28%. The lowest soil EC and pH levels were observed in the treatments with conventional water and no fertilizer and acidified water with urea, respectively. The two-year findings confirm that the sulfur burner device can be an effective solution for reducing the consumption of chemical fertilizers to supply phosphorus and micronutrients from inherent soil resources, ultimately reducing production costs and preventing soil and groundwater pollution. Furthermore, this device can serve as a safer, more efficient, and cost-effective alternative to concentrated sulfuric acid for lowering pH and improving the quality of irrigation water and calcareous soils.