42 
growth, while corn can efficiently utilize ammonia. Further experi- 
mentation with cyanamid as a possible corn fertilizer seems ' espe- 
cially desirable. 
Where used on winter grains with half of the nitrogen supplied 
in the fall and the remainder in the spring, cyanamid gave about 
as good increases on the average as the two standard materials. 
Where all the nitrogen was applied in the fall to wheat and rye, the 
results were even better. This emphasizes the desirability of allow- 
ing a considerable period of time for cyanamid to become available 
in order that it may produce the maximum yields. 
The comparisons between acid phosphate, calcined phosphate, 
and basic slag made in connection with the use of cyanamid showed 
only slight differences in yields, but the experiments were on too 
limited an area and for a period too short to justify a definite state- 
ment as to their relative values. 
The attempts to utilize cyanamid more effectively by the addition 
of oalcium nitrate to mixtures containing it were not entirely suc- 
cessful. This was attributed to the fact that where calcium nitrate 
is used with basic slag the mixture becomes moist during damp 
weather and on drying produces very hard cakes. At the same time 
the moisture probably favors the production of dicyanodiamid from 
the cyanamid present. If a compatible nitrate-cyanamid mixture 
could be developed, such a combination would undoubtedly be more 
desirable than cyanamid alone. In such a mixture the nitrate 
nitrogen would supply the needs of the plants while the cyanamid 
nitrogen was being made available. 
Ammonium nitrate gave results comparable with sodium nitrate 
and ammonium sulphate. It was readily available and no abnormal 
effects were noted. The chief limitation to its use is its property of 
absorbing moisture from the air, making it somewhat unsuitable for 
fertilizer mixtures. This objectionable feature can be partially over- 
• come by either graining and oil coating the material or by manu- 
facturing double or mixed salts from it. 
Double salt, made from ammonium nitrate and ammonium sul- 
phate, produced effects comparable with either of the materials used 
singly. The material is somewhat hygroscopic, but not nearly to the 
same extent as ammonium nitrate. 
The two mixed salts, made from ammonium nitrate and either 
potassium chlorid or potassium sulphate, were of approximately 
equal value. So far as may be judged from the limited use of these 
materials, they are as available as either ammonium nitrate or 
ammonium sulphate. Although somewhat hygroscopic they are less 
objectionable in this respect than ammonium nitrate. 
Ammonium phosphate and ammoniated superphosphate are ex- 
cellent nitrogen carriers. They gave quick responses, good growth, 
and satisfactory yields. The large quantities of phosphorus in the 
materials partially masked the nitrogen effects. 
Ammonium chlorid was as readily available as ammonium sul- 
phate, but on a few plats 40 and SO pounds of ammonia per acre 
showed some toxic effects and gave slightly lower yields than the 
equivalent amount of nitrogen as ammonium sulphate. This may 
have been due to too high a concentration of the chlorid ion, but no 
work was done to determine this point. 
