IDEAL FERTILIZERS 49 



nitrate/ 7 carrying only about 12 per cent, ammonia in- 

 stead of the 15 to 17 per cent, as in the commercially 

 pure calcium nitrate. In both cyanamid and calcium ni- 

 trate the acid radical is used by the plant and the lime 

 left as a neutralizer. 



Dried Blood is organic a packing house by-product. 

 It carries its ammonia in form of nitrogen, but the ma- 

 terial is so finely divided and so congenial to bacteria it 

 becomes available fully as soon as sulphate of ammonia. 

 All organic sources are soil builders, but with the excep- 

 tion of Peruvian guano and tobacco stems, they are at- 

 tended with more or less acidity, animal products less 

 than vegetable matter, and dried blood least of all animal 

 products. 



Tankage is organic, a packing house by-product, 

 carrying both ammonia and phosphoric acid. Its am- 

 monia is in form of nitrogen and is a little more slowly 

 available than sulphate of ammonia. This is a valuable 

 material for use in mixed formulas with nitrate of soda 

 and sulphate of ammonia. About half its phosphoric acid 

 is available when applied, and the rest soon comes into 

 availability through the decomposition of organic matter. 

 There are, ordinarily, at least three grades of tankage 

 on the market, some carrying more actual plant food than 

 the others, but every particle of tankage is of value to 

 the grower as a soil builder. See Dried Blood as to acid 

 tendency. 



Ground Fish Scrap is organic. It carries ammonia 

 and phosphoric acid in same form as tankage. It should 



