Nov. 8,1915 Relation of Sulphur Compounds to Plant Nutrition 
245 
finer parts of the root system from the soil. Such objection would not 
apply to the sand cultures, which therefore gave conclusive evidence of the 
stimulating effect of calcium sulphate upon the root development of rape. 
The benefit to the tops from this salt was much less pronounced, but 
nevertheless definite. As in most other cases, the elemental sulphur 
was detrimental to the plants, presumably because of toxic action. 
There seems to be no doubt that the rape plant has specific need for 
sulphur, which should be met by including sulphates in its fertilizer 
treatment. 
GRAMINEAE 
Barley (Hordeum vulgare ).—One crop was grown upon a set of soils 
which had already produced one crop of peas with fertilizer treatment 
and a second crop without fertilizer. The barley crop was not fertilized, 
as the pea crops had been light. The variety planted was New Zealand 
Chevalier. In Table VII are given the average air-dried weights of the 
yields from duplicate boxes. 
Table XVII. —Average weights {in grams) of air-dried barley crop 
Treatment. 
Straw. 
Grain. 
Weight. 
Relative 
yields 
when con- 
trol^ 100. 
Weight. 
Relative 
yields 
when con¬ 
trol 100. 
1. Control. 
3d. 5 
too 
9 * 5 
IOO 
2. Complete fertilizer. 
59*0 
162 
10. 5 
III 
3. Complete fertilizer+sodium sulphate_ 
67. O 
184 
14 - 5 
153 
4. Complete fertilizer-f-calcium sulphate_ 
62. 5 
171 
15*0 
158 
5. Sodium sulphate only. 
43 * 5 
XI9 
14. 0 
147 
6 . Calcium sulphate only... .1 
3 8 *5 
106 
17. 0 
179 
7. Sulphur only.;. 
39 *o 
107 
i 3 * 5 
142 
The limited data available are insufficient for the deduction of definite 
conclusions concerning the effects of the sulphur supply upon the growth 
of the barley crop. They indicate, however, that sulphur and the sul¬ 
phates here applied had little influence upon the production of straw in 
this crop either when added to a complete-fertilizer ration or when applied 
alone. Conditions were decidedly different in the case of the grain. 
While the production of straw seems to have been limited, this amount 
of straw produced 40 to 80 per cent more grain in the crops receiving 
sulphur and sulphates alone than in the control crops. Likewise, the 
crops receiving sulphates in addition to a complete-fertilizer ration pro¬ 
duced about 40 per cent more grain than those receiving only the com¬ 
plete ration (PI. XXII, fig, 2). 
Oats (Avena saliva ).—This crop was grown upon a set of soils which 
had borne two unsatisfactory barley, crops, the first of which had been 
fertilized. The oat crop was not fertilized. Wisconsin Wonder was 
