Cadmium (Cd) is a trace metal toxic to humans that naturally occurs in agricultural soils. Durum wheat naturally accumulates more Cd in grains than other cereals, and can reach concentrations close to the regulatory limit of 0.18 mg kg-1 set by European Union (EC 1323/2021). In literature, the addition of large amounts of sulfates (S-SO4) to soil was shown to enhance the solubilisation and the availability of Cd for plants, due to the formation of Cd-SO4 complexes. The main objective of our study was to assess if the availability of Cd for durum wheat was changed by S fertilization of cereals, and, if yes, if it was due to sulfates or to the associated counter ions. Two agricultural soils naturally contaminated with Cd were collected in the field: a clay limestone soil and a non- calcareous loamy soil. The effect of two forms of S-SO4 commonly used as S fertilizers (K2SO4 and (NH4)2SO4), and of their respective control (KNO3 and NH4NO3) were applied to soils samples in controlled conditions at agronomic rates. After 1 and 21 days of incubation, total soluble Cd and its free ionic fraction in 0.005 M KNO 3 extract were determined along with the pH and the concentration of soluble carbon and other main chemical elements. In the non-calcareous soil, the solubility of Cd increased both with the S fertilizers and in the controls, suggesting that it was not due to the formation of CdSO4 complexes but to ion exchange between Cd sorbed onto the solid phase and the counter ions (NH4+ and K+) supplied with S fertilizers. In the limestone soil, the solubility of Cd was selectively increased in the (NH4)2SO4 treatment for reasons yet to be determined. A modeling approach using the ORCHESTRA model is underway to highlight the mechanisms of Cd solubilisation in both soils.