EFFECT OF ELEMENTAL SULPHUR AND OF CALCIUM 
SULPHATE ON CERTAIN OF THE HIGHER AND 
LOWER FORMS OF PLANT LIFE 1 
By Walter Pitz, 
Assistant Agricultural Chemist, Agricultural Experiment Station 
of the University of Wisconsin 
• INTRODUCTION 
A study of the literature 2 shows that a number of investigators have 
noted a beneficial effect when elemental sulphur or sulphates are added 
to certain soils. The number of these investigations and also the types 
of soil and plants employed are limited. Certain workers report no 
beneficial effects from the addition of sulphur or sulphates to soil, and in 
isolated cases an injurious effect has been noted. Just how the sulphur 
or its compounds act is little understood, but there are two plausible 
explanations: (i) That it acts as a fertilizer, supplying the sulphur 
needed for plant growth, and (2) that it acts as a corrective agent— 
i. e., it favors beneficial groups of bacteria, while injurious forms are re¬ 
tarded in growth. However, the problem of sulphur and sulphates in agri¬ 
culture is still far from being solved. This is especially true in the case 
of the effect of sulphur and sulphur compounds upon micro-organisms. 
In order to study this phase of the problem, a series of experiments 
was planned. 
PLAN OF WORK 
The object of these experiments was (1) to note the effect of sulphur 
and sulphates upon the soil micro-organisms and on pure cultures of 
legume bacteria, and (2) to note the effect of sulphur and sulphates upon 
the growth of red clover (Trifolium pratense). 
For the experiments with mixed cultures, fresh soil was used as an 
inoculum. For legume bacteria all materials were sterilized, and the 
nutrient medium was inoculated with a pure culture of bacteria from the 
nodules of red clover. 
1 Paper from the Laboratories of Agricultural Bacteriology and Agricultural Chemistry of the Uni¬ 
versity of Wisconsin. 
2 Hart, E. B., and Tottingham, W. E. The relation of sulphur compounds to plant nutrition. In 
Jour. Agr. Research, v. 5, no. 6, pp. 233-250. 1915. Literature cited, p. 249. 
(771) 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
bs 
Vol. V, No. 16 
Jan. 17,1916 
Wis.—3 
