59 

 responded to S also responded to P; he found that elemental S increased 

 the availability of rock phosphate and supplied an essential nutrient 

 to oats and clover on a Leon fine sane (Aerie Haplaquod) . 



Ozaki conducted an extensive greenhouse experiment with seven 

 soils from fields in north and west Florida to evaluate the value and 

 source of S as a nutrient (Ozaki, C. T. 1950. Sulfur fertilization of 

 Florida soils. Master's thesis . University of Florida. Gainesville, 

 Florida). He made the following conclusions from his study: 



1. Oats and clover responded to S on all soils studied. The 

 Ultisols (Ruston and Greenville fine sandy loams') did not 

 produce a definite response to S until the second cutting. 



2. Gypsum applications above 16 kg/ha of S as gypsum did not 

 produce further increases in yield. 



3. All S applications increased S uptake by oats and clover. 



4. S-deficient oats had a higher concentration of N than those 

 plants with adequate S while S-deficient clover had a much 

 lower concentration of N. 



5. All sources of applied S were equally effective in improving 

 the yield of oats and clover (gypsum, elemental S, normal 

 superphosphate, ammonium sulfate, and potassium sulfate). 



6 . Peanuts responded to S applications at pegging time but did 

 not respond to Ca. 



In 1955, Bartlett, working with Neller, concluded a more extensive 

 study of soil S and plant nutrition in Florida (Bartlett, F. D. 1955. 

 Nature and distribution of sulfur in five soil profiles correlated with 

 plant responses. Ph.D. Dissertation. University of Florida. Gaines- 

 ville, Florida). He found about 10% of the total S in Florida soils 

 was extractable with a buffered acetic acid solution; this S correlated 

 well with S uptake by six forage and field crops in a greenhouse experi- 

 ment. Leon (Aerie Haplaquod), Blanton (Grossarenic Paleudult) , and 

 Gainesville (Typic Quartzipsamment) series were the most S-deficient 



