37 

 increased from about 4 million tons in 1950 to just under 18 million 

 tons in 1976, the total amount of sulfur in fertilizers decreased from 

 1.8 to 1.1 million tons for the same period " (Beaton et al., 1974, p. 4). 



This trend does not appear to be as dramatic for Florida. Table 5 

 indicates that while ordinary superphosphate consumption is down 40% 

 from 1950, the use of other S-containing materials has risen in Florida. 

 Most references do not list S-containing fertilizers separately nor do 

 they summarize S applied as is the custom for N, P, and K. Therefore, 

 the total amount of S applied to Florida soils over the years is 

 difficult to estimate. Mixed fertilizer consumption has also increased 

 considerably since 1945. 



Using data from Beaton et al. and data for fertilizer consumption 

 in Florida in 1978 (Crop Reporting Board, 1978), one can estimate that 

 mixed fertilizers and fertilizer materials used in Florida contain an 

 average of 2.2% S. If this S was distributed evenly on the major crop- 

 land in Florida (1,089,300 ha of field crops, hay, citrus, and vege- 

 tables), then approximately 39 kg of S/ha was applied. If major crop- 

 land and fertilized grasslands are included (2,725,300 ha), then this 

 value is only 15 kg/ha. 



Table 5 shows that the total S as a percent of the N + p 7 ° s + 

 K ? + S has decreased from 32.5% in 1950 to 7.2% in 1973 for the south 

 Atlantic states (3eaton et al., 1974). However, concentrated super- 

 phosphate (0-1% S) , ammonium phosphates (0-2% S) , ammonium polyphos- 

 phates (0% S) , etc. are used more as fertilizer materials or in mixes, 

 and these contain very little incidental S. 



The total harvested area of field crops in Florida has increased 

 from 518,000 ha in 1965 to 623,000 ha in 1979 (21% increase) while the 



