35 

 Chao et al. (1962a) studied the movement of S as gypsum througn 



35 



columns of 15 Oregon soils. The depth of S movement was dependent 



on the amount of water moving through the columns and the sulfate 

 adsorbing properties of the soils. When 20 cm of water was applied to 

 a sandy loam soil, 15.2% of the S appeared in the leachate at 51 cm. 

 Less than 5% remained in the upper 10 cm. On the other hand, those 

 soils with a high clay content (greater than 30%) containing 1:1 type 

 minerals and greater than 1 meq/lOOg exchangeable Al retained all of 

 the applied sulfate above 15 cm when 20 cm of water was applied. Lime 

 and phosphate applications increased sulfate leaching as would be 

 expected from knowledge of the adsorption process. Similar leaching 

 losses of sulfates were observed in undisturbed cores of some Austra- 

 lian soils (Peverill et al., 1977) and in two Caribbean soils (Haque 

 and Walmsley, 1974). 



Rhue and Kamprath (1973) studied the effects of different sources 

 of S on leaching of sulfate in two North Carolina soils during the 

 winter. They found that all of the applied S had leached out of the 

 surface 45 cm of a Wagram loamy sand (Arenic Paleudult) 180 days after 

 treatment. Elemental S, 325-mesh and prilled, was oxidized during the 

 winter months, and after 180 days, extractable sulfate-S was at the 

 original level in the upper 45 cm cf surface soil. Oxidation and 

 leaching rates were much slower in a Georgeville silty clay loam 

 (Typic Hapludult) . 



The Wagram loamy sand from the coastal plain of North Carolina 

 would be similar in properties to many of the Ultisols of northern 

 Florida. Winter rainfall in north Florida would be comparable to that 

 in North Carolina. However, the milder temperatures cf Florida would 



