52 
Journal of Agricultural Research 
Vol. XXVIII, No. i 
The rate of nitrate formation at the lowest temperature was exceedingly slow 
in the case of the soil alone and also in the presence of urea. Even after 42 days, 
only about 10 per cent of the added nitrogen was recovered as nitrate nitrogen. 
With the equivalent application of cyanamid no nitrification occurred and even the 
nitrification of the soil organic matter was prevented. At room temperature 
Fig. 5.—Diagram showing the rate of nitrification of cyanamid and urea at different temperatures 
the urea nitrified to the extent of 49 per cent after one month but even after 42 
days none of the cyanamid nitrogen was recovered as nitrate. In this experiment 
the same sample of cyanamid and the same soil type was used as in the previous 
experiments but the nitrification was poor. This may be attributed to the 
difference in the room temperature during the winter and summer months. 
