F p!ants ^ ie Nitrogen as ammonia would be 69.7 and of Nitrogen 



- as dried blood 64.4. 



* 2 These figures possess a very great practical signifi- 



cance, as they have a direct bearing upon the profitable 

 or unprofitable purchase and use of the Nitrogen con- 

 tained in the fertilizers now offered in our market. 



Commercial conditions fix the price of the various 

 Nitrogenous materials. There is no strict relationship 

 as yet between commercial and agricultural values. 



Garbage-tankage, tanned leather scraps and feath- 

 ers are used in large quantities in some of the large 

 fertilizer factories. The Nitrogen in these products is 

 admittedly much less available than is that in dried blood, 

 and its cost to the manufacturers is small. For gar- 

 bage-tankage, leather scraps, feathers, wool waste and 

 peat, prices are merely nominal. The cost of handling 

 and reducing these products to forms capable of being 

 used in mixtures, of course, naturally adds to the cost. 

 These materials should be regarded in the same light 

 as the insoluble phosphates and potash compounds- 

 amendments rather than sources of direct supplies of 

 available plant-food and be paid for accordingly. 



Since their establishment, the Experiment Stations 

 have consistently urged the farmers to be guided in 

 their purchase of fertilizers, not only by the quantities 

 of the constituents present in the mixtures offered, 

 but also by the kind that is used in them, pointing 

 out the importance of selecting brands which contain 

 high percentages of available plant-food, more especially 

 of Nitrogen, because of its relatively greater importance 

 and its higher cost. The results obtained in the inves- 

 tigations referred to emphasize very strongly the wis- 

 dom of such advice in reference to the most valuable 

 element Nitrogen . 



A concrete example will make clearer the commer- 

 cial phases of the question. The analysis of the vari- 

 ous brands sold in the State of New Jersey in a recent 

 year, shows an average of 2.5 per cent, of total Nitrogen, 

 divided as follows: 



Nitrate.. 48% or 19% of the total 



Ammonia 77% or 30% of the total 



Organic 1 . 32% or 51% of the total 



