I02 MAINE AGRICULTURAL EXPERIMENT STATION. 



TRADE VALUATION OF FERTILIZERS. 



In 1894 this Station stopped printing- trade valuations and the 

 reasons therefor were then explained. As letters are occasion- 

 ally received in which correspondents ask for trade valuations, 

 the reasons for not printing them are here briefly restated. 



The chief reason is that coiiniicrcial values are not the same as 

 agricultural values. Trade values are determined by market 

 conditions, the agricultural value is measured by the increase of 

 crop. Printing trade valuations increases the tendency, already 

 far too strong, to purchase fertilizers on the ton basis without 

 regard to the content or form of plant food. The agricultural 

 value of a fertilizer depends upon the amount and form of nitro- 

 gen, phosphoric acid and potash it contains and the use to which 

 it is to be put. The purchase of a fertilizer is really the pur- 

 chase of one or more of these ingredients, and the thing of first 

 importance is not the trade value of a ton, but the kinds and 

 pounds of plant food contained in a ton. 



In the selection of a fertilizer, the first question to be decided 

 is, what use is to be made of it. Is it nitrogen, phosphoric acid 

 or potash that is needed, or is it any two or all three that must 

 be had? Is the fertilizer to supplement farm manures, to act 

 as a "starter" for the crop or must it furnish all the plant food 

 for the crop? 



Having decided just what plant food is needed, it is now time 

 to consult the fertilizer bulletin and see which of the brands 

 there given has an analysis nearest to the required one. In this 

 selection generally only high grade goods (those having high 

 percentages of plant food) should be considered, as high grade 

 goods cannot be made from inferior sources of plant food. 

 Freight costs no more on a ton of goods having 500 pounds of 

 plant food than on a ton having only 200 pounds of plant food, 

 nor is the cost of mixing a ton of high grade goods greater than 

 the cost of mixing low grade goods. 



The final step is to inquire prices and buy the kind which 

 comes nearest to meeting the needs at the lowest price per ton. 

 The cost, although of great importance, is to be considered after 

 the kinds and amounts of plant food needed are decided upon. 



