Nitrogen is the engine of vegetative growth and one of the most critical nutrients in crop production. However, when and how nitrogen is applied during the season makes the difference between maximum efficiency and huge waste. The classic mistake is to apply most or all of the nitrogen upfront, without considering crop stage, weather forecast or yield potential. In early growth stages (BBCH 00–30) nitrogen is essential for root and leaf development. A strong start allows the crop to better capture water and nutrients later. Too much nitrogen at this stage leads to excessive vegetative growth and higher lodging risk. In the intermediate stages (BBCH 31–59), when the crop shifts from vegetative to reproductive growth, nitrogen determines the number of tillers/spikelets and grain filling potential. The most efficient strategy is split application: 30–40 % at/pre-seeding, 40–50 % at tillering/stem elongation, the rest at flag leaf/booting. In late stages excess nitrogen delays maturity, increases disease pressure and lodging risk, and can reduce grain quality. Weather has a huge impact: in wet years leaching can remove 30–70 kg N/ha from the root zone; in dry years unused nitrogen stays on the surface and only produces lush canopy, not grain. Modern tools (greenseeker, N-Sensor, satellite NDVI, drones) allow real-time, zone-specific adjustments — typically saving 15–25 kg N/ha while adding 300–700 kg/ha of grain. Conclusion: the key to profitable and sustainable nitrogen management is delivering the right amount at the right time, exactly when the crop needs it most.