938 
Journal of Agricultural Research 
Vol. XXX, No. 10 
per acre, produced an increase in yield, 
but larger amounts seemed to injure the 
plants. The protein content was in¬ 
creased by moderate applications of 
sulphur and decreased by large 
amounts. Duley (2) has also shown 
that gypsum and sulphur greatly 
increase nodule formation on red clover 
in certain Missouri soils. 
Hall (6) found that the percentage of 
total sulphur in alfalfa hay from vari¬ 
ous parts of the United States varied 
to a considerable degree and that the 
fields producing the heaviest yields 
contained the highest percentages of 
sulphur. The amount of sulphur re¬ 
moved by average crops was found to 
be from 37 to 90 pounds per acre, which 
seems to be in excess of the amount 
returned to the soil by rain. 
Eaton (3) pointed out that most of 
the sulphur in the soil is in the organic 
form and that there is a general cor¬ 
relation between the sulphur and 
organic matter content, soils high in 
organic matter having in general a 
high sulphur content. It was found 
that the application of large amounts 
of gypsum to red clover produced 
plants containing more nitrates, pro¬ 
tein, and sulphates than where small 
amounts were added. Also flowers of 
sulphur and sodium sulphate con¬ 
taining the same amount of sulphur 
as 100 pounds of gypsum per acre and 
gypsum at the rate of 500 pounds per 
acre greatly increased the yield of 
sweet corn. Larger applications of 
flowers of sulphur and sodium sulphate 
gave no increase. 
In regard to beans and peas, Hart 
and Tottingham ( 7 ) found that sul¬ 
phates were beneficial in the production 
of seed and of hay. Calcium sulphate 
was found to be superior to sodium 
sulphate; however, both greatly in¬ 
creased root development and likewise 
produced more hay. Elemental sulphur 
depressed the development of the 
legumes studied except for an apparent 
increase in root development in clover. 
Miller (10) found an increase in the 
nitrogen content and root develop¬ 
ment of clover by the application of 
sulphates. 
Shedd (15) secured an increased 
yield of soy beans in almost every test 
from the application of sulphates or 
sulphur. Sulphatic fertilizers increased 
the sulphur content of soy beans, but 
not necessarily the protein content, as 
would be expected, since sulphur is a 
constituent of protein. In a number 
of cases the per cent of protein in¬ 
creased as the sulphur content in¬ 
creased, but not in the same propor¬ 
tion. Ammonium sulphate was found 
to increase the protein content of soy 
beans to a marked degree. 
Olson and St. John (11) found that 
alfalfa treated with sulphur-containing 
fertilizers produced two or more times 
the quantities of hay on certain Oregon 
soils than was obtained on land un¬ 
treated. Alfalfa treated with sulphur 
contained more protein than where no 
sulphur was applied and the plants had 
a darker green color which was evident 
in the cured hay. 
Pitz (12) concluded that calcium sul¬ 
phate greatly increased root develop¬ 
ment in clover grown in artificial media, 
but concentrations as high as 0.1 per 
cent retarded root growth. Elemental 
sulphur gave a slight increase in yield 
of red clover on Miami silt loam, but 
there was no difference in size or num¬ 
ber of nodules on the roots. Large 
amounts of elemental sulphur de¬ 
creased the total number of bacteria 
growing on agar plates, but produced an 
increase in ammonification with con¬ 
centrations of 0.05 per cent. This was 
accompanied by a decrease in nitrate 
formation, which was thought to be 
due to the acidity produced. 
Erdman (J) obtained an increased 
yield of alfalfa hay at each cutting 
with gypsum, but the effect was more 
pronounced on the first cutting than on 
subsequent cuttings. Apparently 200- 
pound applications were better than 
500-pound applications. Gypsum did 
not affect the nitrogen content of the 
hay. He also found that gypsum was 
favorable to red clover in several in¬ 
stances and that it had practically no 
effect on the crude protein content with 
or without lime. It was found that 
gypsum applied in ordinary amounts 
had no effect upon the types of bacte¬ 
ria instrumental in breaking down 
organic matter nor was there any ap¬ 
parent effect upon the ammonifiers or 
nitrifiers. This is practically in ac¬ 
cord with results reported by Lipman 
(9) who states that from 200 to 500 
pounds of sulphur per acre did not ma¬ 
terially increase the lime requirement, 
but heavier applications did increase 
the lime requirement. 
PLAN OF INVESTIGATION 
In order to determine the effect of 
sulphur on alfalfa production a green¬ 
house experiment was planned con¬ 
sisting of 12 treatments of five pots 
each. Each pot contained 12.24 kg. of 
the surface 7 inches of Oswego silt 
loam, a black, productive residual soil 
derived from weathered shale. Soil 
samples were taken at the beginning 
of the experiment for the purpose of 
