Zawartość i wydajność tłuszczu z nasion rzepaku jarego w warunkach nawożenia azotem i siarką

Abstract

A three-year field experiment was conducted in northern Poland on degraded black soil, valuation class IIIb, with very high content of phosphorus and potassium, low content of sulphur, and neutral pH. The experiment was carried out in a split-block design with two factors, in four replications. The aim of the study was to evaluate the effect of different application rates of nitrogen (factor A: 0, 60, 120 and 180 kg N·ha-1) and sulphur (factor B: 0, 20 and 60 kg S·ha-1), taking into account different means of its application (soil application before sowing and foliar application of sulphur) on the oil content and yield in seeds of the Star cultivar of rapeseed. Somewhat higher oil content and yield were observed in the case of soil application of sulphur than for foliar application. In each growing season nitrogen and sulphur applied independently significantly increased the oil content and yield from the seeds of spring rapeseed as compared to the control. Irrespective of the means of application, application of sulphur together with nitrogen generally resulted in higher oil content and yield than application of either of these nutrients alone, but their interaction was not confirmed statistically. The observed beneficial effect of sulphur applied alone and together with nitrogen on important criteria of spring rapeseed quality substantiates the need to include sulphur in fertilization of this species.