2 BULLETIN 1180, U. S. DEPARTMENT OF AGRICULTURE. 
ties during that period were largely limited to the Government, and 
as a part of the program for providing an adequate supply of explo- 
sives the War Department constructed two nitrogen-fixation plants 
at Muscle Shoals and Sheffield, Ala., in 1917 and 1918. While these 
plants were constructed for the immediate purpose of furnishing 
explosives it was expected that they would be utilized for the pro- 
duction of nitrogen fertilizer in peace times. Although not operating, 
they represent a potential source of about 48,000 tons of fixed nitro- 
gen per annum. This quantity of nitrogen is equivalent to about 
240,000 tons of ammonium sulphate or 308,000 tons of sodium nitrate 
and is approximately equal to 30 per cent of the nitrogen consumed 
as fertilizer in this country in 1919. These plants were designed to 
produce ammonium nitrate for high explosives as their final product, 
with calcium cyanamid, ammonia, and nitric acid as intermediate 
products. 
At the close of the war the problem of utilizing these nitrogen- 
fixation plants for the production of nitrogen fertilizer arose, and this 
immediately raised the question of the fertilizing value of the pro- 
ducts which might be made there. The direct product of the larger 
and more important of the two plants is calcium cyanamid, from 
which ammonia can be readily obtained, and this, in turn, can be 
oxidized to form nitric acid. This one plant, therefore, provides a 
source of cyanamid nitrogen, ammonia nitrogen, and nitrate nitrogen, 
representing all the forms of fixed nitrogen obtainable by the present 
fixation processes, and hence the problem of its agricultural utiliza- 
tion involves a consideration of the fertilizing value of cyanamid and 
various ammonium and nitrate compounds. Considerable investi- 
gational work, particularly on cyanamid, has been reported by a 
number of European experiment stations, but with the exception of 
cyanamid these new materials have been studied very little under 
American conditions. It was to obtain information concerning their 
fertilizing value that the field experiments described in this bulletin 
were made. 
The experiments were begun in the spring of 1919 by the Nitrate 
Division of the Ordnance Office, United States Department of War, 
in which the Government's fixed-nitrogen activities were then 
centered, working in cooperation with the Bureau of Plant Industry 
of the United States Department of Agriculture. The work was 
conducted on the reservations at the two nitrate plants, where the 
necessary land, labor, and equipment were available, and covered a 
period of three years, at the end of which time it was discontinued. 
During the first summer the experiments dealt wholly with cyanamid 
and ammonium nitrate, but the following two years the scope of the 
work was enlarged to include a number of other synthetic-nitrogen 
products which appeared to have fertilizer possibilities. 
FERTILIZERS USED. 
Experiments were made with the following nitrogen materials: 
Cyanamid, ammonium nitrate, ammonium phosphate, ammoniated 
superphosphate, ammonium chlorid, a double salt consisting of 
ammonium nitrate and ammonium sulphate, a mixed salt obtained 
from ammonium nitrate and potassium chlorid, a mixed salt obtained 
from ammonium nitrate and potassium sulphate, urea, and Ure- 
