Keywords: Cereals, Grass, Oilseed rape, Sulfur responses, Sulfur fertilizers.

Sulfur (S) deficiency has become widespread in many countries in Europe since the 1980s. This is due to a massive decrease in the atmospheric deposition of sulfur, a change in the use of fertilizers that contain low sulfur and increased crop yields. This paper reviews crop responses to sulfur in Europe, focusing on oilseed rape, cereals and grass, on which most field trials have been carried out. Multicut grass for silage has been shown to be highly susceptible to sulfur deficiency, and yield responses to sulfur of between 5 and 30% are common in Ireland, the UK and other countries. Oilseed rape is also susceptible to sulfur deficiency, and sulfur fertilisation can produce a dramatic yield response under deficiency conditions. Sulfur deficiency in oilseed rape has been widely reported in France, Germany, Denmark and the UK. Although cereals have a lower requirement for sulfur, responses to sulfur application of between 5 and 30% have been obtained in France, and also increasingly in the UK and Germany. In general, field trials across different countries have shown that oilseed rape responds to sulfur applications up to 30 kg S/ha, cereals up to 20 kg S/ha, and grass between 20 and 40 kg S/ha. Sulfur deficiency not only affects yield, but also impacts on crop quality. It has been demonstrated that the sulfur status of wheat grain has an important influence on bread-making quality. Grass low in sulfur is nutritionally inferior for animals. Maintaining a sufficient sulfur status also has a positive effect on the quality of legumes and sugar beet. In contrast, too much sulfur may have a negative effect on rapeseed due to increased concentrations of glucosinolates. Occurrence of sulfur deficiency is more likely to be found on light or shallow soils with low organic matter content, in areas of low atmospheric deposition of sulfur and with excessive winter rainfall. Because atmospheric inputs of sulfur will continue to decrease further in Europe, the deficit in the sulfur input/output is likely to increase, unless sulfur fertilizers are used.

F. J. Zhao, S. P. McGrath, M. M. A. Blake-Kalff, Division of Agriculture and the Environment, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
A. Link, Research Center Hanninghof, Hydro Agri GmbH & Co. KG, D-48249 Dülmen, Germany.
M. Tucker, Hydro Agri (UK) Limited, Immingham, N. E. Lincolnshire DN40 2NS, United Kingdom.

27 pages, 9 figures, 4 tables, 77 references.