FIXATION OF ATMOSPHERIC NITROGEN 99 



Nitrate of soda, Chili saltpetre and sulphate 

 of ammonia have regularly produced higher 

 yields and better utilization of the nitrogen 

 than cyanamide. 



If the value cf nitric nitrogen be expressed 

 by 100, the value of the nitrogen in cyanamide 

 is represented by 90. The lime nitrogen acts 

 a little more feebly when it is decomposed in the 

 soil, giving rise to the formation of dicyanamide 

 resulting from the action of carbonic acid, hu- 

 mic acid, heat and the absence of bacteria. The 

 factors which favor the action of cyanamide 

 are uniform distribution, perfect mixing of the 

 manure with the soil, sufficient moisture to the 

 soil, and a loamy soil rich in bacteria, spreading at 

 the latest on the 15th day of February for winter 

 plants. 



Cyanamide does not suit humic acid soils, 

 where its action is uncertain and where it may 

 poison plants. For the same reason its use is 

 not recommended in light, sandy, somewhat 

 torpid soils, especially those with an acid reac- 

 tion. All other soils, especially loose friable soils, 

 which contain enough lime and are regularly 

 manured with farmyard dung, may be manured 

 with cyanamide. The quantity to use per acre 

 is 135 to 274 lb., according to the fertility of 

 the soil. 



As cyanamide gives off an enormous amount 

 of dust which is possibly the most unpleasant 

 defect of this manure, the best thing to do, if 



