166 



Ulrich, A., and L. 0. Hylton. 1968. Sulphur nutrition of Italian 



ryegrass measured by growth and mineral content. Plant and Soil 

 29:274-284. 



Urone, P. 1975. The effects of air pollution and the sulfur oxides 

 problems in Florida. Fla. Dept. of Environ. Reg. Train. Ses. 

 Ser. University of Florida. Gainesville, Florida. 



Urone, P., and M. A. Kenney. 1980. Atmospheric pollution. In 



A. E. S. Green (ed.) Coal burning issues. Univ. Presses of 

 Florida. Gainesville, Florida. 



Vishniac, W. , and M. Santer. 1957. The thiobacilli. Bacteriol. Rev. 

 21:195-213. 



Volk, G. M. , and C. E. Bell. 1945. Some major factors in the leaching 

 of calcium, potassium, sulfur, and nitrogen from sandy soils. 

 Fla. Agr. Exp. Sta. bul. no. 416. University of Florida. 

 Gainesville, Florida. 



Walker, D. R. , and C. F. Bentley. 1961. Sulphur fractions of legumes 

 as indicators of sulphur deficiency. Can. J. Soil Sci. 41: 

 164-168. 



Walker, T. W. , and A. F. R. Adams. 1958. Studies on soil organic 



matter: I. Influence of phosphorus content of parent material on 

 accumulations of carbon, nitrogen, sulfur, and organic phosphorus 

 in grassland soils. Soil Sci. 85:307-318. 



Williams, C. H. , and C. M. Donald. 1957. Changes in organic matter 

 and pH in a podzolic soil as influenced by subterranean clover 

 and superphosphate. Aust. J. Agri. Res. 8:179-189. 



Williams, C. H. , and A. Steinbergs. 1958. Sulphur and phosphorus in 

 some eastern Australian soils. Aust. J. Agri. Res. 9:483-491. 



1959. Soil Sulphur fractions as chemical indices of avail- 



able sulphur in some Australian soils. Aust. J. Agri. Res. 10: 

 340-352. 



Williams, C. H. , E. G. Williams, and N. M. Scott. 1960. Carbon, 

 nitrogen, sulphur, and phosphorus in some Scottish soils. 

 J. Soil Sci. 11:334-346. 



Wolt, J. D., and F. Adams. 1979. The release of sulfate from soil- 

 applied basaluminite and alunite. Soil Sci. Soc . Am. J. 43: 

 118-121. 



Woodhouse, W. W. , Jr. 1969. Long-term fertility requirements of 

 coastal bermudagrass. III. Sulfur. Agron. J. 61:705-708. 



Yoon, R. H., T. Salman, and G. Donnay. 1979. Predicting points of 

 zero charge of oxides and hydroxides. J. Coll. and Interface 

 Sci. 70:483-493. 



