460 
Journal oj Agricultural Research 
Vol. XXX, No. 5 
EFFECT OF SULPHUR AND GYPSUM ON 
HYDROGEN-ION CONCENTRATION 
Table VIII gives the results of the 
determinations of the hydrogen-ion 
concentration in the samples of drain¬ 
age water obtained from the pots in 
experiment 1 during the month of June, 
and in the leached soils at the close 
of the experiments. 
Before the treatments were made 
the soil used in these experiments had 
a P H of 7. The range of experimental 
error for the colorimetric method of 
determining hydrogen-ion concentra¬ 
tion is usually considered to be 0.2 
P H . By taking this error into consid¬ 
eration and examining the determina¬ 
tions given for the duplicate treat¬ 
ments, it is noted that in every case at 
least one of these determinations falls 
within the 0.2 P H limit. Therefore it 
can not be definitely said that any of 
the treatments increased the hydrogen- 
ion concentration in this soil or in the 
drainage water obtained during the 
month of June. It is surprising that 
Considerable acidity did not develop 
in those soils receiving large additions 
of sulphur. A possible explanation for 
this fact is the high reserve supply of 
basic materials in the Palouse silt 
loam. As sulphuric acid was produced 
it was immediately neutralized by the 
bases present. Owing to its large sup¬ 
ply of basic materials, this soil may 
receive considerable quantities of sul¬ 
phur without showing the need of 
limestone to correct acid conditions. 
The data given in Table VIII show 
also that there was insufficient acidity 
developed from sulphofication to bring 
about any solvent action on the native 
soil potassium and that the increase 
of this element, owing to the various 
treatments noted in Table IV, proba¬ 
bly resulted indirectly from the forma¬ 
tion of salts. 
DISCUSSION OF THE CURVES 
Each of the tables from III to VII, 
inclusive, gives a column representing 
the total water-soluble elements which 
were recovered in both experiments. 
The data giving the average of the 
duplicate treatments have been used 
Table VIII.— Hydrogen-ion concentration in the drainage water for June and in 
the soils at the end of the experiments 
Experiment 1 
(field pots) 
Experi- 
‘ ment2 
(green 
house 
Pot 
Treatment (pounds per acre) 
pots) 
IN 0. 
Drainage 
water 
for June 
Soil 
extracts 
Soil 
extracts 
i 
Hontrol _________—_— 
Ph 
6.9 
Ph 
6.9 
Ph 
6.9 
2 
6.9 
7.3 
7.1 
A veraee _ 
6.9 
7.1 
7.0 
- - 
— — ——— 
....- ■ 
3 
4 
TTninnmlfltfirl snlnhnr 18fi _ 
6.7 
7.2 
6.7 
6.7 
7.3 
6.5 
Average_ 
6.7 
7.1 
6.6 
* K 
Tnnnnlotor? snlnhnr 1SQ _ ___ 
6.6 
7.4 
(TT 
o 
6 
6.7 
7.0 
6.9 
6. 65 
7.2 
6.8 
7 1 
Uninoculated sulphur 1000________—_ 
6.7 
7.1 
6.7 
4 
8 
4.6 
6.9 
6.6 
5. 65 
7.0 
6. 65 
Q 
Trmpnlfltpd snlnhnr 1015 ____ 
6.5 
7.1 
6PT 
10 
6.7 
6.9 
6.7 
6.6 
7.0 
6.7 
1 1 
ftvnsum 1 000 _ _ 
6.7 
7.4 
7.3 
XI 
12 
6.8 
7.2 
6.9 
6. 75 
7.3 
7.1 
