38 FARM AND SCHOOL PROBLEMS. 



the plant food in a high grade fertilizer can be purchased cheaper 

 per pound than in a low grade fertilizer. 



Purchasing a brand of fertilizer that has less than 2 per cent 

 ammonia or potash is useless and a waste of money. 



PROBLEMS. 



1. An inspection of fertilizers in Vermont in 1908 showed that the 

 average selling price of mixed fertilizers was $31.24 per ton, but the 

 materials for mixing could have been purchased at retail in Boston or 

 New York for $20.75. What was the per cent cost of the mixed fertilizer 

 above cost of materials. 



The value of a fertilizer as a profitable investment depends upon 

 the value of the crop to 'be raised. 



2. If a certain fertilizer is used and increases the value of a crop 

 10 per cent; what will be the difference in gain, between a corn crop 

 that amounts to $25 per acre and a truck crop that amounts to $150 

 per acre? 



When a farmer decides to use fertilizer it is just as important to 

 know the requirement of a certain crop as it is to know the condition 

 of the soil. For instance, corn, oats, rape and potatoes will each require 

 a different formula. 



Home Mixing of Fertilizers. 



Although there has been a vigorous and prolonged protest 

 from certain sources against the practice of "home mixing" 

 fertilizers, the economy in the purchase of plant foods, the 

 thoroughness with which the operation can be performed by the 

 farmer himself and the greater efficiency of the home mixed 

 fertilizer over the factory mixed brands frequently found on the 

 market, have been so repeatedly and conclusively demonstrated 

 that there can now be no logical or tenable objection advanced 

 against the practice. It has been urged "That the compounding 

 of fertilizers is an intricate and difficult operation, requiring 

 extensive acquaintance with chemistry, costly machinery and 

 great technical skill. When applied to the production and manu- 

 facture of fertilizing materials that is the selection and quarry- 

 ing, grinding and acidulation of phosphatic rock ; the drying and 

 grinding of slaughterhouse refuse, the production and refining 

 of such materials as nitrate of soda, sulphate of ammonia and 

 muriate of potash the statement is entirely correct, because all 



