A RISK ASSESSMENT OF SULFUR DEFICIENCY IN CEREALS USING SOIL AND ATMOSPHERIC DEPOSITION DATA

A qualitative model was used to assess the risk of S deficiency in cer eals in Britain. A risk index was generated for each of 6301 soil data points by considering the inputs of S from atmospheric deposition, th e content of soil organic matter, and factors influencing the potentia l leaching of sulphate, i.e. soil type, texture, pH and annual rainfal l. The results show that currently 11% of the British land area is at high risk of S deficiency, and a further 22% at medium risk. The high risk areas are in south-east Scotland, the Scottish Borders, East Angl ia, the Welsh Borders and south-west England. These agree well with th e distribution of reported incidences of S deficiency in cereals. If t he UK target for reduction in SO2 emissions by the year 2003 is met, t he model predicts that the high and medium risk areas will increase to 23 and 27%, respectively. Thus, agricultural use of S-containing fert ilizers is likely to increase in importance in the near future.