452 
Journal oj Agricultural Research 
Vol. XXX, No. 5 
Pot No. 
Treatment 
Pounds 
per acre 
1 and 2_ 
Control_ 
3 and 4_ 
Uninoculated sulphur_ 
186 
5 and 6_ 
Inoculated sulphur.. 
189 
7 and 8_ 
Uninoculated sulphur_ 
1,000 
9 and 10.... 
Inoculated sulphur..... 
1,015 
1,000 
11 and 12 .. 
Gypsum__ 
The soils in pots Nos. 3, 4, 5, 6, 11, 
and 12 received equivalent amounts of 
sulphur, the calculations being made on 
the basis that chemically pure gypsum, 
which was used in these experiments, 
contained 18.6 per cent of sulphur. 
The samples of uninoculated and in¬ 
oculated sulphur were obtained from the 
Texas Gulf Sulphur Co. Inoculated 
sulphur is supposed to contain large 
numbers of efficient sulphur-oxidizing 
bacteria which give it the ability to 
act quicker than uninoculated sulphur. 
The soils in the pots placed in the 
field were exposed to natural weather 
conditions and remained undisturbed 
from December 5, 1922, to June 18, 
1923. On the latter date a composite 
soil sample was taken from each pot, 
and water extractions were made for 
the purpose of studying the amount of 
water-soluble plant food material in the 
soils at the close of the experiment. 
During the progress of the experiment 
the drainage water from each pot for 
each month was collected, filtered 
through Buchner funnels, and stored in 
large bottles in the laboratory. A 
small quantity of toluol was added to 
each bottle to inhibit bacterial action. 
EXPERIMENT 2 
On December 9, 1922, an exact dup¬ 
lication of experiment 1 was started in 
the greenhouse to verify and elaborate 
the results obtained from the soils ex¬ 
posed to natural weather conditions. 
After the treatments were made the 
soils were adjusted to the optimum 
moisture content, and for a period of 
72 days the moisture content was main¬ 
tained by additions of distilled water 
to weight. At the end of this time all 
of the soils were flooded with definite 
amounts of distilled water for 4 con¬ 
secutive days, and the teachings thus 
obtained were treated and analyzed as 
in the case of the drainage water se¬ 
cured from the pots in experiment 1. 
Soil extracts wese made from these 
soils after they were allowed to dry. 
ANALYTICAL WORK 
The analytical work for these experi¬ 
ments involved (1) the analyses of the 
drainage water obtained form the pots 
which were exposed to field conditions; 
(2) the analyses of the leachings from 
the pots which were placed in the green¬ 
house; and (3) the analyses of the 
water extracts made from the soils at 
the close of both experiments. These 
analyses included determinations of 
sulphur, nitrogen, phosphorous, potas¬ 
sium, calcium, and magnesium. Colori¬ 
metric hydrogen-ion determinations 
were made on samples of soil taken 
from the pots at the conclusion of 
both experiments and also on samples 
of the drainage water obtained from 
each pot for the month of June, 1923. 
A rain gauge of the standard United 
States Weather Bureau type was 
placed beside the pots used in experi¬ 
ment 1. Records were kept of the 
amount of precipitation, and samples 
of rain water for each month were 
analyzed for total sulphur. A few 
ammonia and nitrate determinations 
were made on the first samples, but 
since only traces of these compounds 
were present the study of nitrogen in 
the rain water was abandoned. 
DISCUSSION OF RESULTS 
This study was limited to the surface 
6% inches of soil, and it should be 
understood that the entire amount of 
elements reported in the drainage 
water was not necessarily totally lost 
to crops. Under actual field condi¬ 
tions some of the water-soluble ele¬ 
ments may be returned to the surface 
soil from the deeper soil layers by capil¬ 
larity. It is believed, however, that 
the results secured are sufficient to aid 
materially in obtaining a better under¬ 
standing of the probable effects of sul¬ 
phur on soil fertility. 
Climatic conditions at the Washing¬ 
ton Agricultural Experiment Station 
are ideal for lysimeter studies. The 
annual average rainfall is 21.49 inches. 
The heavy rains, when leaching is most 
apt to occur, come during the period ex¬ 
tending from November to June. The 
season during which these experiments 
were made was exceptionally dry in 
the fall, and the winter rains did not 
begin until early in December, or im¬ 
mediately after the pots were placed in 
the field. Therefore as far as the per¬ 
colation studies are concerned this 
investigation may be considered as rep¬ 
resenting the work of one year. 
The rainfall and the total sulphur of 
the rain and snow covering the period 
from November 29, 1922, to June 18, 
1923, are found in Table I. 
