ji VOLUME LXXIII NUMBER 2 



THE 



BOTANICAL GAZETTE 



. . February ig22 



SULPHUR AS A FACTOR IN SOIL FERTILITY 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 289 



John Woodard 

 Introduction 



Although sulphur was recognized as an essential element in 

 plant nutrition as early as the middle of the nineteenth century, 

 the use of sulphur and sulphur compounds as fertilizers has never 

 become general. Analyses for sulphur in soils have generally been 

 low, yet when compared with the sulphur in the ash of plants, the 

 amount present in the soil seemed sufficient for all the needs of the 

 crop. The use of gypsum as a fertilizer, however, was quite exten- 

 sive for a time, following the discovery of its beneficial effect on 

 plants. Browne (13) credits this discovery to a clergjnnan in 

 Germany in 1768. From there it spread to France and Great 

 Britain, and was brought to the United States by Benjamin 

 Franklin, who used it on his farm near Philadelphia. For a time 

 gypsum was extensively used as a fertilizer both in Europe and the 

 United States and gave remarkable results. Griffiths (25) reports 

 experiments by Schubert in Germany, and Crocker (15) refers 

 to the experiments of Judge Peters, John Binns, and Edmund 

 RuFFiN in the United States. All these men obtained remarkable 

 results with gypsum on legumes. 



The use of gypsum alone, however, soon failed to increase crop 

 yields, and investigators seeking for an explanation came to the 

 conclusion that the gypsum acts chemically on the phosphorus or 

 potassium compounds in the soil and liberates either phosphorus or 



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