EFFECT OF DIFFERENT LEVEL OF NITROGEN FERTILIZER ON GRAIN YIELD OF WHEAT IN CENTRAL PART OF OLTENIA

Nitrogen is an important nutrient that plays a significant role in maximizing crop yields worldwide. Optimizing nitrogen fertilization ensures suitable grain yields and reduces environmental pollution. The aim of the research was to investigate the effect of different nitrogen levels on grain yield of wheat and nitrogen use efficiency. The field research was performed at Agricultural Research and Development Station.imnic on a reddish preluvosoil, during three consecutive growing seasons. Five nitrogen levels: 0 (control), 30, 60, 90 and 120 kg N/ha were used. Statistical analysis showed that nitrogen levels had a significant effect on grain yield in all years of study. On average, the three-year data indicated that nitrogen fertilizers generated increases of 30-114%, representing 7.8-29.2 q/ha compared to the control. The highest agronomic efficiency of nitrogen (33.7 kg/kg) was at a level of 60 kg N/ha, which is considered a rational application in terms of nitrogen emissions to the environment.