The experimental material was made up of ‘Korweta’ winter wheat grain samples from 2000/2001-2002/2003 field experiments, while the experimental factors were: 5 nitrogen fertilization doses from 0 to 160 kg N·ha^-1 applied during vegetative development stages (0; 40 = 40 – 0 – 0 – 0; 80 = 40 – 40 – 0 – 0; 120 = 40 – 40 – 40 – 0; 160 = 40 – 40 – 40 – 40, the first dose was sown at the beginning of vegetation, the next one – after 14, 28 and 42 days) and 4 variants of late fertilization applied at earing and at the end of flowering (0; 40 = 40 – 0; 40 = 0 – 40; 80 = 40 – 40). Nitrogen fertilization, both early and late, had an inconsiderable effect on the physical properties of grain and falling number. Much bigger differentiation of results was caused by weather conditions. A favorable effect of early fertilization on quality traits of grain and flour was observed. The total protein content, gluten content and Zeleny test values increased after the application of 80 to 160 kg·ha^-1 of nitrogen, yet the improvement of farinograph traits (dough resistance and softening and valorimeter value) was recorded for the nitrogen dose of 120 and 160 kg·ha^-1. Late nitrogen application much improved the wheat grain quality; even if at early development stages low nitrogen fertilization was used. The effect of early nitrogen fertilization on wheat grain quality traits was similar irrespective of the weather conditions during the vegetation period. A positive reaction of wheat to late nitrogen fertilization was stronger in the years in which weather conditions were unfavorable for obtaining high quality grain. A high protein yield was recorded when nitrogen fertilization was minimum 160 kg·ha^-1, half of which was applied at the early dose.

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