Two field experiments were conducted in a silty clay soil at a private farm at Al Arid, Belqas Center, Dakahlia Governorate, Arab Republic of Egypt, during the two successive seasons of 2019/2020 and 2020/2021, to study the impact of water deficit (WD), organic fertilization as vermicompost and some soil additions (without, HA and EM), moreover their interactions on growth, yield and its components and quality of potato Spunta cultivar. Data cleared that water deficit treatments have significant effect on vegetative growth, yield and its components and quality parameters in both seasons. The maximum means of these characters are recorded as a result of irrigation of potato plants regularly in both seasons, except, proline content in tubers of potato, which resulted under the influence of irrigation deficit in both seasons. While, vermicompost addition increased significantly all studied characters except, proline, nitrate (NO₃) and nitrite (NO₂) contents in tubers of potato, in both seasons. As for the impact of soil additions (without, HA and EM), the same data are increased significantly with HA compared to other treatments, except, proline, nitrate (NO₃) and nitrite (NO₂) contents in tubers and which were recorded for them the lowest values with the addition of EM in both seasons. As for the interaction among full irrigation plus vermicompost and HA soil addition treatment gave the best values of all studied characters. However, the interaction among irrigation deficit plus vermicompost and HA addition gave superiority compared with plants have full irrigation without vermicompost and without soil addition treatments.