THE PURCHASE AND MIXING OF FERTILIZERS 199 



Table 42. — Comparative Values of Low-Grade, Medium and 

 High-Grade Fertilizers 



In mixing fertilizers in a factory, it is customary to incor- 

 porate with the carriers of plant nutrients more or less material 

 that has no influence on plant growth, but that serves to di- 

 lute the mixture and to prevent it from becoming damp by 

 the absorption of moisture, and also to prevent the chemical 

 interaction of the constituents. This material is called a filler. 



254. Fertilizer inspection and control. — Most of the 

 states have enacted legislation providing for the inspection 

 and control of the sale of commercial fertilizers. Each 

 brand of fertilizer, that sells for $5.00 or more a ton, must 

 pay a state license fee and each bag must bear a tag stating 

 the guaranteed percentage of nitrogen, phosphoric acid and 

 potash that the fertilizer contains, and giving some informa- 

 tion in regard to their solubility. 



There is little uniformity in the requirements of the dif- 

 ferent states. In some states a very detailed statement of 

 the composition of the fertilizer and the solubility of its 

 constituents is required. The following information is 

 called for by some of the states. 



Percentage of nitrogen in the following forms : 



