34 

 Florida, to estimate the amounts of S added to Florida soils through 

 precipitation, and to evaluate the importance of oceanic aerosols and 

 biogenically-produced S to Florida rainfall chemistry. While the 

 deposition of H and excess sulfate (i.e., total sulfate minus sea-salt 

 sulfate) in Florida rainfall is 30 to 90% of the deposition rates in 

 the northeastern United States, the acidity of rainfall in Florida has 

 increased markedly in the past 25 years; the average sulfate concen- 

 trations have increased 450%. The relative annual deposition of S on 

 Florida soils in bulk precipitation at five sites from 1952 to 1955 

 and from 1978 to 1979 and the relative acidity of rainfall are shown 

 in Fig. 3 (Brezonik et al., 1980). 



Northern Florida receives more than 1.5 times as much S as sulfate 

 annually from bulk precipitation as southern Florida (8.4 and 5.5 kg/ha, 

 respectively). Northern Florida is the most industrialized area of the 

 state, and accounts for 85% of the total anthropogenic S emissions in 

 the state. Coastal areas receive only around 4 kg/ha in rainfall. 

 These data were based on samples collected from 24 sites throughout the 

 state. The bulk of this S in north Florida (69%) fell during the 

 summer months when it could be of most benefit as a nutrient to growing 

 plants. This period also corresponds to the season of maximum rainfall 

 in Florida. Sea sulfate was estimated to constitute only a small por- 

 tion of the total sulfate in Florida precipitation. The percentage of 

 sea sulfate in precipitation decreased rapidly from coastal to inland 

 sites . 



The occurrence of acid rainfall, which is directly related to 

 atmospheric S, is more frequent in northern counties than in southern 

 and coastal regions of the state. The most acidic rainfall in 1978 



