236 
Journal of Agricultural Research 
Vol. V, No. 6 
that in sterilized soil the addition of elemental sulphur had no effect in 
increasing plant growth, confirming their idea that elemental sulphur 
acted through some influence on the soil flora. Demolon (2) believes 
that sulphur not only acts by stimulating the soil flora but, in addition, 
acts as a source of needed sulphur after it has been oxidized in the soil. 
He showed conclusively that flowers of sulphur would gradually oxidize 
to sulphates in the soil, a statement which we have confirmed and which 
likewise has been shown by Lint (8) to be true. The fact that elemental 
sulphur is oxidized in the soil probably has direct bearing on the necessity 
for the use or presence of adequate quantities of lime or other basic 
material in a soil receiving this treatment. This may not apply to 
all crops, but might properly explain the results secured by Wheeler, 
Hartwell, and Moore (16), who showed that there was injury to cereals 
following the application of elemental sulphur for the prevention of 
potato scab, unless a considerable quantity of lime had been used in the 
soil. From the South Oregon Experiment Station, Reimer (10) reported 
large increases in the yield of alfalfa by the direct use of elemental 
sulphur. Whether these experiments were conducted on soils of high 
basicity has not been reported. 
The possibility of injury to the crop by partial oxidation of the ele¬ 
mental sulphur to sulphite must always be kept in mind. Thalau (15) 
has shown that sulphites of ammonium and calcium are toxic to plants 
in dilute solution, but probably are not so toxic in the soil itself. The 
fate of the elemental sulphur introduced into a soil will ultimately be 
its oxidation to a sulphate, but the formation of intermediate compounds 
and their toxic effect may account for the contradictory results that 
have been recorded from its use. For example, Janicaud, Hiltner, and 
Gronover (7) report deleterious effects with tomatoes from the use of 
elemental sulphur, and some of the results of Sherbakoff (14) in the 
treatment of potatoes for scab are of a similar order. Consequently, 
the attempted introduction of elemental sulphur as a source of sulphur 
in plant nutrition should, in our judgment, be viewed with caution. 
The basis for this statement will be amplified in the following report 
of experimental work. After this manuscript had been prepared, the 
work of Shedd (13), of the Kentucky Agricultural Experiment Station, 
was made public. In this work use was made of a number of sulphates 
and sulphids, and of elemental sulphur. Good results from the use of 
a number of these materials are reported. Elemental sulphur and gyp¬ 
sum were helpful to tobacco, and elemental sulphur was materially 
beneficial to turnips on the soil investigated. Clover on this soil was 
not helped by sulphur-containing fertilizers, with the exception of a 
benefit from the use of potassium sulphate. Other plants, such as mus¬ 
tard, cabbage, and radish, showed increased growth with sulphur- 
containing materials. 
