Nov. s, 1915 Relation of Sulphur Compounds to Plant Nutrition 
239 
different set of the same type of soil, but which had produced two crops 
of rape (both fertilized) and three crops of radishes, the last radish crop 
having been fertilized. The soils were limed for this crop. The yields 
of air-dried crops are given in Table I. 
Table I .—Average weights (in grams) of air-dried bean crops 
Treatment. 
Seed. 
Straw and pods. 
Crop 
A. 
Crop 
Crop 
Crop 
Aver¬ 
age 
rela¬ 
tive 
yields 
of 
crops. 
Crop 
A. 
Crop 
B. 
Crop 
C. 
Crop 
D. 
Aver¬ 
age 
rela¬ 
tive 
yields 
of 
crops. 
1. Control. 
6.4 
0.7 
7 -i 
5*3 
100 
15*7 
12.4 
34-7 
26.8 
100 
2. Complete fertilizer. 
8.0 
5-7 
13.8 
*5-9 
223— 
21.41 
19.1 
42* S 
45*8 
144 
3. Complete fertilizer + sodium sul¬ 
6.9 
3*4 
12 .9 
12.8 
185 
18.8 
20.1 
46.8 
43*3 
144 
phate. 
4. Complete fertilizer + calcium sul¬ 
10.4 
6.3 
17-3 
10.1 
226— 
24.4 
22.3 
44-3 
40.8 
147 
phate. 
5. Sodium sulphate only. 
7-i 
5-9 
13-3 
6.6 
169 
19. 2 
17.1 
3i- 7 
26.0 
105 
6. Calcium sulphate only. 
6.6 
6.1 
ix-7 
4.6 
149 
14.8 
20.2 
31-8 
21. 5 
89 
7. Sulphur only. 
3 -o 
4 -x 
1.9 
0.9 
Si 
17-9 
20.3 
2 5-3 
19*3 
92 
The relative yields of seed showed irregular results from the appli¬ 
cation of the sulphates. When added to the usual complete-fertilizer 
ration, sodium sulphate depressed growth, while calcium sulphate 
slightly favored it. When applied alone, both salts gave results decidedly 
better than the control untreated soils. In this case the soluble sodium 
sulphate gave better results than the comparatively insoluble calcium 
sulphate. It seems possible that the superior results from the sodium 
sulphate applied alone as compared with its effect when added to the 
complete-fertilizer treatment may have been due to an unfavorable 
excessive accumulation of soluble salts in the latter case which might 
not occur when it was added alone. 
The relative yields of straw from this crop showed no significant 
effects which might be due to the added sulphates. Sulphur alone was 
decidedly injurious to the beans. The effect is more noticeable in the 
case of the grain than with the straw. This might be expected to obtain, 
since the plants already weakened in general vitality would probably 
be depressed in the power of reproduction. This was more probably 
due to sulphites and other toxic oxidation products of the sulphur than 
to the sulphur itself. It could not be due merely to the acidity of the 
soil produced by oxidation of the sulphur, for it occurred with crop D, 
which was limed. 
Ceovkr (Trifolium pratense ).—The variety grown was Medium Red. 
Crop A was grown on fresh fertilized and limed soil. Crop B followed 
crop A on the same soil without fertilizer treatment, but with the addi¬ 
tion of fresh soil in boxes 13 and 14, to which calcium carbonate and 
elemental sulphur were applied. Crop C was grown on completely 
