The absorption of Sulphate (S) by plants depends on the desorption of S from soils. We studied the effects of parent material and extraction time on the release of adsorbed sulphate from the soils developed across different parent materials namely; Chad formation (CF), Basement complex rock (BCR) and Kerri-Kerri formation (KKF) in the Sudan savanna. In the desorption experiment, soils were allowed to adsorb sulphate as in the adsorption studies and the adsorbed sulphate was extracted by shaking for 30, 60, 150, 180 and 240 minutes with 15 ml Ca(H2PO4)2 solutions containing 500 mg P L-1, respectively. The results revealed that sulphate desorption decreased with increasing shaking time (range; 34.96 to 19.09 mg/kg) in all the studied soils. The rate of desorption was also characterized by initial rapid desorption with > 65% being desorbed in the first 30 minutes which was considered as a good index for describing S desorption maximum followed by a slow-release (nutrient) that progressed gradually up to 240 minutes. The trend of the magnitude of the rate of desorption by the soil parent materials was in descending order: CF>BCR>KKF. Therefore, we concluded that the rate of sulphate desorption in studied soils were affected by parent material and time. Therefore, the application of Sulphur fertilizers should be based on the impacts of these factors for effective precision of S diagnosis and thus, enhance crop yields.