Winter oilseed rape is characterized by a huge nitrogen balance surplus. This work aimed to improve its nitrogen efficiency by targeted nitrogen nutrition using either nitrate or urea to fertilize30 field-grown lines. Nitrate was expected to stimulate root cytokinin synthesis. These phytohormones (1) delay plant senescence and (2)promote branching when exported to shoots, anticipating (1) prolonged root activity and (2) increased potential sites for pod and seed formation. In contrast, urea was assumed to induce earlier senescence and lower the yield potential. Indicated by xylem sap analyzes, apparently highly available nitrate stimulated cytokinin translocation over the short-term, while nitrogen availability from urea fertilizer lasted for longer. As branching was not consistently affected by the nitrogen form, and if so seed yield was compensated by other parameters, its economic and ecological advantages over nitrate make urea a valuable fertilizer for oilseed rape production.