CROPS AND SOIL IMPROVEMENT 



for their various forms and carriers. A pound of 

 nitrogen in dried blood may have its valuation 

 fixed at a figure 50 per cent higher than that of 

 a pound of nitrogen in nitrate of soda simply 

 because the dried blood sells at a price per ton 

 that makes that difference. It is true commercial 

 value that is sought, and that may be very differ- 

 ent from agricultural value. 



The mixed fertilizer of the manufacturer has 

 its content of plant-food known by analysis. 

 Its number of pounds of the various constituents 

 in a ton is known, and the retail price per pound 

 of these substances has been fixed. The com- 

 mercial value per ton can then be determined, 

 provided proper allowance is made for cost of 

 mixing and bagging. The individual must pay 

 in addition the freight, and usually a considerable 

 sum for unnecessarily costly methods of distri- 

 bution and collection. 



A Bit of Arithmetic. This paragraph is in- 

 tended to serve the man who is willing to be reason- 

 ably near right if he cannot be wholly so : A ton 

 is 2000 pounds, and one per cent is 20 pounds. In 

 dealing with fertilizers it is the practice to call 

 20 pounds, or one per cent of a ton, a unit, and to 

 base the price of the nitrogen, and phosphoric 



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