Detailed analyses have been conducted on productive moisture reserves, water consumption, and (WUE) coefficients of soybean and sunflower crops depending on the immediate and residual effects of mineral and organic fertilizers, as well as their influence on yield. The study was conducted in the Central Forest-Steppe of Ukraine on leached typical chernozem. It was found that soybean plants consume the largest portion of available soil moisture from the 0–20 cm and 0–50 cm layers during the growing season. Sunflower, due to its well-developed root system, utilizes the moisture reserves most effectively from the entire 0–100 cm soil profile. Moreover, in the 101–150 cm soil layer, sunflower extracted an additional 51–58 mm of moisture compared to the initial reserves. This physiological trait allows sunflower to be efficiently placed after row crops such as soybean in crop rotation systems. The application of N40P40K40 fertilizers under soybean improved root system development and enabled better use of moisture from deeper soil layers, resulting in yields of 3.39 and 3.45 t ha-1. In contrast, without fertilizer application (since 1976 and 2006), yields declined significantly to 2.38 and 2.48 t ha-1, which corresponds to 69 % and 72 % of the maximum potential yield, respectively. These results demonstrate that soybean requires annual fertilization, as the absence of nutrients leads to reduced plant height and lower yields. Sunflower yields under fertilized conditions ranged from 3.38 to 3.81 t ha-1. The residual effect of previously applied fertilizers remained stable (2.73–3.18 t ha-1), confirming the long-term efficiency of fertilization and the high adaptability of sunflower to residual soil nutrient supply. The findings justify the placement of sunflower after row crops, particularly soybean, in crop rotations and support the development of adaptive fertilization and rotation strategies under unstable water availability conditions.