Effect of Sulphur and Micronutrients Fertilization on Yield and Fat Content in Winter Rape Seeds (Brassica napus L.)

Three-year strict experiments with winter rapeseed were conducted in three experimental stations. In the research, winter rape fertilization with elemental sulphur (S) in the doses: 20, 40 and 60 kg S/ha, boron (B) - in the dose of 2 kg B/ha and copper (Cu) - 5 kg Cu/ha were applied. Microelements were introduced separately, in treatments B and Cu, as well as in combination B + Cu. The experimental soils featured low content of sulphate sulphur SO₄^2- -S and boron, medium and low copper content. Rapeseed fertilization with sulphur, boron and copper resulted in their increased concentration in plants. Sulphur at 40 and 60 kg S/ha doses affected the increase in oilseed rape grain yield by 11-12% compared to the not fertilized treatment. The dose of 20 kg S/ha did not show any significant influence on yield. The yield increased by more than 10% in the comparison to the treatment without B and Cu, was obtained due to boron, as well as combination of boron and copper fertilization. A significant increase in fat content, in relation to not fertilized treatment, ranking from 1.0-1.4% dry matter, was recorded after fertilization with the highest sulphur dose - 60 kg S/ha, as well as after application of boron and copper fertilization.