jan. 17, i 9 i6 Effect of Sulphur and Calcium Sulphate on Plants 773 
Table II .—Acidity of soil treated with elemental sulphur 
Treatment. 
Calcium oxid 
necessary to 
neutralize add 
in 10 gm. of soil. 
Untreated. 
Gm. 
0. OOOO 
. OOOO 
. OOOO 
. 0011 
. 0369 
.0668 
Given o.oi per cent of sulphur. 
.05 per cent of sulphur. 
. 10 per cent of sulphur. 
. 50 per cent of sulphur. 
1.00 per cent of sulphur. 
The results of these determinations show that the acidity produced 
by the oxidation of elemental sulphur to sulphate is proportional to 
the amount of sulphur added. In the samples to which 0.01 and 0.05 
per cent of sulphur had been added, the soil contained enough lime to 
neutralize the acidity. 
Change in reaction is probably the cause of the decrease in the number 
of the soil organisms. Abundant mold growth was found on the surface 
of the acid soils. 
Table III shows that calcium sulphate in the quantities used has no 
effect on the production of ammonia in the soil. Elemental sulphur, 
however, in concentrations of 0.5 and 1 per cent increases the production 
of ammonia to a marked degree. This increase is noticeable after 44 
days. 
Table III .—Effect of calcium sulphate and elemental sulphur on the production of 
ammonia in the soil 
Quantity (in milligrams) of ammonia nitrogen per ioo 
gm. of soil after— 
Treatment. 
12 days. 
30 days. 
44 days. 
72 days. 
93 days. 
Untreated. 
3-99 
3 *i 9 
3*40 
3*21 
3*23 
Given o.oi per cent of caldum sulphate- 
3 *i 9 
2.38 
3*32 
2.80 
3*48 
. 05 per cent of calcium sulphate.,.. 
3-19 
2.21 
3.06 
3-06 
3 - 57 
. 10 per cent of caldum sulphate_ 
3-82 
2.38 
3*23 
3*32 
3*23 
, 50 per cent of caldum sulphate_ 
3-19 
2.29 
3*36 
3*40 
3*57 
1.00 per cent of caldum sulphate_ 
3. 82 
2.21 
3.06 
3*23 
3 - 4 ® 
Untreated. 
3*97 
3*19 
3.12 
2-97 
3-40 
Given o. oi per cent of sulphur. 
3*91 
2.38 
3 * T 9 
2. 72 
3 - 23 
. 05 per cent of sulphur. 
3 * 19 
2.29 
3.06 
2.46 
3 * 23 
. zo per cent of sulphur. 
3- 06 
2. 21 
3*23 
2*55 
3* 16 
. 50 per cent of sulphur. 
3.82 
2.89 
5 * 95 
7-31 
8.26 
1.00 per cent of sulphur. 
3*95 
2.89 
6. 80 
7 * 3 i 
9-52 
The data in Table IV show that calcium sulphate in the quantities 
used does not materially affect the formation of nitrates in the soil. Ele¬ 
mental sulphur, on the other hand, in concentrations of 0.5 and 1 per 
cent decreases nitrate formation. This decrease is noticeable after 30 
days. Previous to this time the sulphur does not seem to injure nitrate 
formation. Concentrations of sulphur lower than 0.5 per cent have no 
