Effect of nitrogen and sulphur fertilization on the yield and composition of winter oilseed rape

A field experiment was conducted to assess the effects of varying levels of sulphur (S) and nitrogen (N) supply on oilseed rape (Brassica napus L. var. Rafal) grown in a soil assessed to be in the low category for plant available sulphate (SO4). There were no significant effects on crop yield as a result of applied S for any of the treatments. This was probably due to a significant input of atmospheric S as a result of the wetter than average year. However, there were significant compositional effects on total S, total N and sulphate‐sulphur (SO4‐S) which has implications for the supply of S from soil which can often display a range of S availabilities. Effects on composition were most marked as the crop reached maturity.