Decomposition of Proteins 



17] 



The tnu- stnictiire of iiroa luis been postulated, however, to be as 

 follows: 



AH 



HN = C< I 



Cyanamide readily breaks down in the soil to ammonia, whieh 

 is th(Mi nitrified \irtually quantitatively. Cyanamide may first be 



40 



^y^2^^ + dicyanodia 



mide 



Days 



Fig. 73. Accumulation of ammonia from cyanamide and dried blood, as influ- 

 enced by the presence of dicyantjdiarnide (from Cowie). 



decomposed in the soil into urea by a purely chemical process, under 

 the influence of catalyzers, or it may polymerize into dicyanodiamide 

 (especially in the presence of catalyzers such as ZnClo). 



Soils differ markedly in the rate with which they decompose cal- 

 cium cyanamide, but very few are deficient in the required catalyst, 

 which changes the cyanamide to urea. The urea is transformed in 

 the soil to ammonia within a few days, especially in soils active micro- 

 biologically. Nitrate formation proceeds more slowly in soils treated 

 with cyanamide, the retardation depending on the soil and the 

 environmental conditions. A great many soil organisms are capable 

 of decomposing dicyanodiamide. 



