Productivity of spring brown mustard depending on application of sulphur-containing fertilizer

In 2020–2022 we studied the effect of ammonium sulphate on the productivity of the spring brown mustard variety Yunona on leached chernozem of the Western Ciscaucasia. It was found that the most effective agricultural practice is the foliar split application of this fertilizer: N21S24 at the seedling stage and N21S24 at the stage of stem extension. This agricultural practice contributed to a significant increase in the main indicators of the crop yield structure: the number of productive branches and pods per a plant by 28.6 and 13.8% respectively; the number of seeds in a pod – by 15.8% and the thousand-seed weight – by 24%. As a result, the crop yield increased by 0.31 t/ha in 2020, 0.44 t/ha in 2021 and 0.43 t/ha in 2022, with a three-year average of 0.39 t/ha. In addition, the oil yield increased by 0.20 t/ha, oil content of seeds by 1.9%, and essential oil content of seeds by 0.06%.