22 



Sulphate of ammonia, Dissolved bone, 



Nitrate of soda. Ground phosphate rock, 



Azotine, Acid phosphate, 



Dried blood, Refuse bone black. 



Cotton seed meal. High grade sulphate of potash. 



Castor pomace, Muriate of potash. 



Linseed meal, Sulphate of potash-magnesia, 



Dry ground fish, Kainit, 



Bone and tankage, Sylvinite, 



Crude saltpetre. 



A comparison of the trade values of the essential elements of 

 plant food for 1906, with the previous season, shows that the only 

 variation is in nitrogen in form of nitrates which is one-half cent 

 lower in cost than during the previous season, 1905. The other 

 forms of nitrogen as well as the different forms of phosphoric acid 

 and potassium oxide cost the same as in the previous year. 



Valuation. The approximate value of a compound fertilizer or 

 any material used for fertilizing purposes is obtained by calculating 

 the value of each of the three essential elements of plant food (nitro- 

 gen, phosphoric acid and potassium oxide, including the different 

 forms of each wherever different forms are recognized in the table) 

 in one hundred pounds of the fertilizer, and multiplying each product 

 by twenty to change it to a ton basis. The sum of these values will 

 give the total approximate value of the fertilizer per ton at the prin- 

 cipal places of distribution. 



In case of bone and tankage, we calculate separately the nitrogen 

 and phosphoric acid value of each grade of mechanical fineness by 

 multiplying the pounds of nitrogen and phosphoric acid per ton by 

 the per cent, of each grade, and multiply these products by the trade 

 values per pound, of nitrogen and phosphoric acid in each grade, 

 and express the final product in cents. Adding the separate values 

 of each grade of both ingredients, we have the valuation of the 

 material in question. 



In figuring the commercial value of a compound fertilizer, a suit- 

 able amount should be added to cover the expenses incurred in the 

 manufacture and sale of the goods. 



The trade value of a fertilizer does not necessarily indicate its 

 exact agricultural value. The trade value of a given fertilizer 



