This field experiment was carried out in the years 2001–2002 at the Experimental Station of Zawady belonging to the University of Podlasie in Siedlce. The experiment was run in the “split-blok” system in 3 sequences. Two factors were taken into consideration: I factor – fertilization rate of nitrogen: 0 kg N ha-1, 40 kg N ha-1, 80 kg N ha-1, 120 kg N ha-1, 160 kg N ha-1, 60 kg N ha-1 + foliar application of fertizers. II factor – cultivars of spring wheat: Banti, Henika, Jasna, Eta.