Sulfur Management In the UK and Europe.

Sulfur deposition from the atmosphere has decreased dramatically since the early 1970s in Western Europe. Consequently, the S balance has tilted toward deficit in many agricultural systems in recent decades. Changes in the S balance will be illustrated using a >160 years long-term experiment. Sulfur is now a limiting nutrient for Brassica crops, cereals and grassland in many areas of the UK and other European countries. Yield responses to S have been evaluated for different crops. Where deficiency is likely to occur, the benefit to cost ratio of applying S fertilizers is very favourable based on yield response alone. In addition, S deficiency adversely impacts on the quality of crops. The S supply influences the composition of gluten proteins in wheat grain and consequently the bread-making quality. Sulfur-deficient wheat grain accumulates high levels of the free amino acid asparagine, which is a precursor of the carcinogen acrylamide formed during baking. Sulfur deficiency affects malting quality of barley by influencing the enzymatic hydrolysis of starch, and the flavour. In the UK, S fertilizers are applied to over 60% and 40% of the crop areas for canola and cereals, respectively. Recommendations for S fertilization are based on a simple model that includes the data for atmospheric deposition, soil, climatic and crop S requirement, and by using plant tissue analysis.