86 FERTILIZERS. 



COMMERCIAL AND AGRICULTULRAL VALUES OP FERTIL- 



IZERS. 



The prices in the above tables are the market or com- 

 mercial value of the three elements. Says Professor Cook, 

 " The agricultural value of a fertilizer in other words, the 

 profit which its use secures for a farmer in an increased 

 crop is in no way indicated by its market price. Reliable 

 information concerning agricultural values must be sought 

 upon the farm, and not by the guesses of the farmer, but 

 from the actual weight of the crops grown under known 

 conditions, and upon accurately measured areas." Hot or 

 cold, wet or dry, seasons, will affect the results obtained 

 from fertilizers, but cannot be said to affect their commer- 

 cial value ; in fact, the average of numerous experiments 

 demonstrates that these extremes have a greater effect on 

 crops fed on barn manure than on those fed by fertilizers. 



WHERE TO OBTAIN OUR FERTILIZING MATERIAL AT THE 

 LOWEST COST. 



The table (84) directs us for what substances to inquire 

 when we go into the general market. But there are out- 

 side sources which are more or less accessible to the aver- 

 age farmer. Even in the varied products of the farm, the 

 three elements vary greatly in cost. 



Professor George Caldwell makes the following esti- 

 mates of the value of nitrogen, potash, and phosphoric 

 acid in various combinations. Assuming that in 1884 

 potash could be purchased at 5 cents per pound, phos- 

 phoric acid at 9, and nitrogen at from 16 to 18 cents, 

 then, at these rates, 



