The study was based on a three-year field experiment conducted on degraded black soil, classified as class IIIb soil in the Polish soil valuation system, with neutral pH, high content of phosphorus and potassium, average content of magnesium, and low content of sulphur. The two-factor experiment was carried out in northern Poland (52°73' N; 18°88' E), in a split-block design with four replications. The preceding crop each year was sugar beet. The aim of the study was to evaluate the effect of varied levels of nitrogen (first factor - 0, 60, 120 and 180 kg ha-1) and sulphur (second factor - 0, 20 and 60 kg ha-1) applied to the soil and onto the leaves on the content and ratio of these elements in the seeds of the Star cultivar of spring rapeseed. Little variation was noted between growing seasons in the content of nitrogen and sulphur and in their proportions in the seeds. Application of nitrogen alone (without sulphur) and combined application of nitrogen with sulphur caused an increase in the nitrogen content in the seeds and in the N:S ratio. The sulphur content in the seeds of the plants fertilized with nitrogen and sulphur together was significantly higher than in the seeds of the plants fertilized with nitrogen alone and lower than in the plants fertilized with sulphur alone. The highest N:S ratios were obtained in the seeds of plants fertilized with nitrogen alone, and the lowest - following the application of sulphur alone. Application of nitrogen or nitrogen and sulphur caused an increase in the N:S ratio towards optimal values for fodder crops. The method of sulphur application did not significantly affect its content in the rapeseeds or the N:S ratio

25.4.2020