abstract: The present study involved a detailed analysis of foliar feeding of the winter oilseed rape cultivar ‘Kana’ combined with different regimes of fertilization with calcium and magnesium compounds. Foliar fertilizers, INSOL PK + 5% urea solution and EKOSOL U, were applied three times during the growing period and four different soil fertilization treatments were used: control without fertilization, NPK, NPK + MgSO₄ · 7H₂O, and NPK + CaO + MgO. This study was carried out based on a three-year field experiment on medium soil with a pH of 4.2 in 1 mole KCl · dm^-3 and with the grain-size distribution of silt loam. The soil was characterized by a low content of available phosphorus and potassium as well as a very low content of sulfur and magnesium. The soil fertilization treatments used and the foliar fertilizers resulted in differences in the yield parameters, the macronutrient content in seed and straw as well as in the protein and oil content in seed. This study found the best production effects and quality parameters in the cultivation of winter oilseed rape in the treatment with the use of magnesium lime in the fertilizer dose. The foliar fertilizers caused greater differences in seed yield as well as in protein and oil content and yield than in the mineral composition.