Using the saline water for irrigation purposes negatively affects soil properties; however, these effects can be mitigated through appropriate management practices. Therefore, the present study aimed to optimize the phosphogypsum-to-humic acid ratio to minimize the adverse effects of saline irrigation water on soil chemical properties and cauliflower growth. A two-factorial field experiment was carried out during the autumn season of 2024 in Anbar Governorate, Iraq. The texture of the soil under study was sandy loam. The experiment was designed in a complete block design with three replications. The first factor involved three levels of water irrigation salinity, i.e., 2.70, 5.50, and 7.50 dS m⁻¹. The second factor was the level of humic acid, namely 0.0, 0.25, and 0.50 g L⁻¹, while the third factor was phosphogypsum at 0.0, 0.25, and 0.50 g L⁻¹. Soil chemical properties such as EC, Ca, Mg, Na, SAR, SO₄, Cl, and HCO₃ and growth and yield components were measured. The results revealed that the combined application of humic acid and phosphogypsum was very important in mitigating the adverse impact of saline irrigation water. Specifically, such treatments decreased electrical conductivity (EC), sodium adsorption ratio (SAR), sulfate (SO₄⁻), chloride (Cl⁻), bicarbonate (HCO₃⁻), and sodium (Na⁺) in the soil. On the other hand, there was an increase in calcium (Ca²⁺) levels. Moreover, T4 (0.25 g L⁻¹ phosphogypsum and 0.50 g L⁻¹ humic acid) showed better performance over other treatments. Moreover, it has not only enhanced the soil chemical properties but also the growth characteristics and yield components of..