Oilseed rape (Brassica napus L.) is an oil crop highly demanding for nutrients, especially nitrogen. In the current global context, nitrogen has to be used by farmers in the most efficient way, the rate having to be correlated with the environmental conditions and the yield objectives of the farmer, and the most effective nitrogen fertilizer having to be used. Starting from these ideas, the aim of the performed research was to identify the effects of nitrogen rates on grain yield at winter oilseed rape by using Urea and Urea NG as nitrogen fertilizer in the specific growing conditions of South Romania. In this respect, research was performed in field conditions in South Romania in the years 2023, 2024, and 2025, this having the following experimental factors: Factor A. Nitrogen fertilizer type (a1- no nitrogen fertilizer used - control variant; a2- Urea; a3- Urea NG); Factor B. Nitrogen rate (b1- 100 kg/ha; b2- 130 kg/ha; b3- 160 kg/ha; b4- 190 kg/ha). The field experiment was organized as subdivided macro-plots with 3 replications, each replication having 0.33 ha. For Urea fertilizer, the nitrogen rate of 130 kg/ha (60 kg applied in autumn and 70 kg applied early in the spring) under less favourable climatic conditions, and the nitrogen rate of 160 kg/ha (60 kg applied in autumn and 100 kg applied early in the spring) under favourable climatic conditions were highlighted. For Urea NG fertilizer, the nitrogen rate of 160 kg/ha was highlighted regardless the climatic conditions of the year. Nitrogen is utilized by the oilseed rape plants according to the climatic conditions of the year: the better the climatic conditions of the year, the better the plants use the nitrogen, and higher grain yields are obtained at higher nitrogen rates.

winter oilseed rape, fertilization, nitrogen rate, nitrogen fertilizer, grain yield

agronomy

Presentation: poster