Effects of timing of sulfur application and nitrogen fertilization on yield and quality of barley

The effect of S and N application on the redistribution of S and the effect of N application and time of S application (from sowing to the middle of heading) on yield and quality of spring barley (Hordeum vulgare L.) was investigated in pot experiments. Nitrogen and sulphur had a clear interactive effect on the yield of all plant parts with little or no effect of S at low N application rates and similar low effect of N without S application. About 70% of leaf N was redistributed to the ears in plants growing at adequate S supply compared with about 35% of leaf N in S-deficient plants. The proportion of ear N and S originating from the redistribution of leaf N and S was 49% and 23%, respectively. Deficiency symptoms were observed already at the beginning of tillering at the highest levels of N application and the number of ears per plant clearly decreased by delayed S application. Sulphur applied when the flag leaf was first visible compensated for this and prevented yield reductions. The higher the N levels, the earlier S had to be applied for yield reductions to be avoided. The contents of the S-containing amino acids cysteine and methionine increased when S was applied later than at sowing. Sulphur application had a relatively higher impact on grain quality than on dry matter yield and this was more so the later the application occurred