VOLUME LXXIII NUMBER 2 
JHE 
BOTANICAL GAZETTE 
February 1922 
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 clergyman 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 
S8ypsum was extensively used as a fertilizer both in Europe and the 
United States and gave remarkable results. GrirFrrHs (25) reports 
experiments by ScnusEert in Germany, and CRocKER (15) refers 
to the experiments of Judge PETERS, JoHN Binns, and EpmMunD 
Rurrin 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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