CHAPTER VII. 



Nitrification of Cyanamid Nitrogen. 



While some of the fertilizing effect of Cyanamid may be 

 due to the presence of urea and ammonium salts, nitrification 

 of cyanamide and its decomposition products may take place 

 very readily in the soil under favorable conditions, providing 

 the concentration of nitrogen is not too great. This is shown 

 in an experiment by Wagner, which was carried out as 

 follows :^ 



Two hundred and fifty grams of sandy-loam soil was mixed 

 with 5 grams of marl and the quantity of nitrogen salts shown 

 in the table below. Each salt was well mixed with 2 grams of 

 gypsum before application in order to facilitate distribution. 

 The mixtures were placed in cylindrical glass vessels 6^^ cm. 

 in diameter and 17 cm. high, moistened with 75 cc. water, and 

 covered with 50 grams unfertilized earth. The vessels were 

 allowed to stand at room temperature and the evaporated 

 water was replaced from time to time. After 12, 20, and 33 

 days respectively samples were drawn from each series and 

 analyzed for nitrate nitrogen. After subtracting the figures 

 obtained in the unfertilized control vessels the following 

 results were obtained: 



With the sodium nitrate 

 Nitrate nitrogen as NO at loo, the other fertilizers 



(cctti,) gave as nitrate nitrogen 



After After After After After After 



Fertilizer 12 20 33 12 20 33 



application days days days days days days 



0.05 grams nitrogen as 



sodium nitrate.... 23.7 23.9 24.7 100 100 100 

 0.05 grams nitrogen as 

 sulphate of am- 

 monia 20.8 22.5 — 88 94 — 



0.0125 grams nitrogen 



as Cyanamid 3.9 5.9 5.9 66 99 96 



0.025 grams nitrogen 



as Cyanamid 4.1 9.9 11.2 35 83 91 



0.05 grams nitrogen as 



Cyanamid 0.3 6.3 14.9 i 26 60 



^ Landw. Vers. Stat. Vol. 66, No. 4 and 5, 1907. 



