The article presents the results of a study on the productivity of winter crops from the Brassicaceae family under different fertilization rates and the influence of agroecological factors during the growing seasons. The experiments were conducted in 2019–2023 at the Nizhyn Agrotechnical Institute, a separate unit of the National University of Life and Environmental Sciences of Ukraine (Chernihiv region). Wintercress (Barbarea vulgaris) cv. Oriana, winter rapeseed hybrid Mercedes, and typhon (B. rapa ssp. oleifera f. biennis × (B. rapa ssp. rapifera × B. rapa ssp. pekinensis)) cv. Orakam were cultivated with 15 cm row spacing under three fertilization regimes: no fertilizer (control), N80P60K60, and N120P90K90. Among all the Brassicaceae crops studied, typhon showed the best seed yield (3.89 t/ha) under the N80P60K60 fertilization rate. While both field cress and rapeseed responded positively to additional fertilization, their yield increases of 0.11 and 0.17 t/ha respectively did not justify the costs of additional mineral fertilizer. Typhon also showed a lower yield response under the higher N120P90K90 rate compared to the moderate N80P60K60 rate. Energy output from aboveground biomass and oil yield from Brassicaceae seeds were significantly influenced by the fertilization regime. These parameters increased with higher fertilization rates – from N80P60K60 to N120P90K90. However, the economic efficiency of increasing fertilizer doses requires separate analysis. The study showed that the best conditions for realizing the biological potential and achieving high seed yield and energy output in the aboveground biomass of typhon cv. Orakam and the winter rapeseed hybrid Mercedes were achieved under fertilization with either N80P60K60 or N120P90K90. Under these conditions, seed production and biomass energy accumulation occurred with high plasticity, and overall, the cultivation conditions corresponded to intensive farming systems. This promoted effective realization of the crops’ biological potential and efficient use of technological elements, particularly fertilization.