The Bulletin 7 



tions of the availability of the water-insoluble organic nitrogen iu the 

 samples of fertilizers taken for analysis. In this way we are largely able 

 to differentiate between the good and the bad ammoniates and to distin- 

 guish those forms which are readily available from those more diffi- 

 cultly so. 



VALUATIONS 



To have a basis for comparing the values of different fertilizer ma- 

 terials and fertilizers, it is necessary to assign prices to the three vahi- 

 able constituents of fertilizers — ammonia, phosphoric acid, and potash. 

 These figures, expressing relative value per ton, are not intended to rep- 

 resent crop-producing power, or agricultural value, but are estimates of 

 the commercial value of ammonia, phosphoric acid and potash in the ma- 

 terials supplying them. These values are only approximate, as the cost 

 of fertilizing materials is liable to change, as other commerical pro- 

 ducts are, but they are believed to fairly represent the cost of making 

 and putting fertilizers on the market. They are based on a careful exam- 

 ination of trade conditions, wholesale and retail, and upon quotations of 

 manufacture. , 



Relative value per ton, or the figures showing this, represent the prices 

 on board the cars at the factory, in retail lots of five tons or less, for 

 cash. 



To make a complete fertilizer the factories have to mix together in 

 proper proportions materials containing ammonia, phosphoric acid, and 

 potash. This costs something. For this reason it is thought well to 

 have two sets of valuations — one for the raw or unmixed materials, such 

 as acid phosphate, kainit, cotton-seed meal, etc., and one for mixed 

 fertilizers. 



Valuations for 1917 



hi Unmixed or Raw Materials 



For phosphoric acid in acid phosphate 4i/^ cents per pound 



For phosphoric acid in bone meal and Peruvian Guano 4 cents per pound 

 For nitrogen 20 cents per pound 



In Mixed Fertilizers 



For phosphoric acid 5 cents per pound 



For nitrogen 21 cents per pound 



For potash 25 cents per pound 



HOW RELATIVE VALUE IS CALCULATED 



In the calculation of relative value it is only necessary to remember 

 that so many per cent means the same number of pounds per hundred, 

 and that there are twenty hundred pounds in one ton (2,000 pounds). 



