CYANAMID — manufacture:, CHEMISTRY AND USES 63 



0.0125 grams nitrogen per 250 grams of soil is equivalent 

 to a fertilization of about 90 pounds of nitrogen per acre. 

 With this large application, even, nitrification of the Cyanamid 

 is complete in twenty days. Larger applications require a 

 longer period, but are of no practical interest. The above 

 results must be considered relatively to each other and not as 

 absolute values, since the conditions were probably very favor- 

 able to nitrification. 



A similar experiment is reported by Muntz and Nottin.^ 

 They found that when 0.25 grams of nitrogen per kilogram of 

 soil was used, the relative amount of nitrification in 5 months 

 for different fertilizers was as follows : 



Per cent. 



Ammonium sulphate 100 



Calcium cyanamide 88 



Dried blood 66 



Roasted leather 26 



The above fertilization is equivalent to about 450 pounds of 

 nitrogen per acre, and has no significance to practical agricul- 

 ture. 



When, however, smaller amounts of Cyanamid were applied, 

 nitrification was very rapid, and further, the bacteria rapidly 

 adjusted themselves to the changed environment and enorm- 

 ously increased their ability to nitrify Cyanamid nitrogen, even 

 when successively increasing doses were applied. This is 

 shown in the following table : 



Amount cyanamid Amount 



nitrogen applied nitrogen present Nitrate nitrogen 



each time at analysis before per kg. of earth 



Date applied grams new application by analysis 



January 17 0.06 — — 



January 26 0.06 0.06 — 



February 7 o.io 0.12 o.oi 



March 3 0.12 0.22 0.18 



April 2 0.22 0.34 0.37 



April 25 ^. 0.40 0.56 0.58 



May 23 — 0.96 0.81 



* Annales de I'lnstitut National Agronomique, 2nd Series, Vol. VI, 

 No. I, 1907. 



