SULPHUR AS A FACTOR THAT AFFECTS NITROGEN EFFECTIVENESS IN SPRING RAPESEED AGROTECHNICS. PART I. CHOSEN YIELD COMPONENTS
Strict, three-year-long field experiment was performed on degraded Phaeozems, IIIb soil valuation class, with pH ranging from 6.5 to 7.1, of high richness in phosphorus and potassium, medium in magnesium, and low in sulphur. The experiment was carried out in a split-block design with two factors in four repetitions. The aim of the study was to evaluate the effect of various doses of nitrogen (0, 60, 120, and 180 kg·ha-1) and sulphur (0, 20, and 60 kg·ha-1), taking into account their different application methods (in-soil and as foliar fertiliser), on the yield components of spring rapeseed cultivar Star. Fertilisation only with nitrogen significantly increased the values of all the studied components, while the sulphur-only fertilisation increased the number of seeds in siliques, as well as the mass of 1000 grains. The number of seeds per silique in none of the research years was significantly affected by the interaction between nitrogen and sulphur. As far as other characteristics are concerned, considering sulphur alongside nitrogen fertilisation, in general, resulted in a significant increase in their values, in comparison with the control plants.