No. 4.] COMMERCIAL FERTILIZERS. 115 



THE PROFITABLE USE OF COMMERCIAL FERTILIZERS. 



BY DR. E. B. VOORHEES, NEW BRUNSWICK^ N. J. 



I have chosen the subject '^ The Profitable Use of Commer- 

 cial Fertilizers " in order that I might, as far as possible, 

 eliminate any scientific discussion which might have a tend- 

 ency to confuse or in any way to lead your thoughts away 

 from the very practical question of the relation of fertilizers 

 to improved crops and to profit, and also that I may talk to 

 you as a farmer to farmers. Naturally, it is necessary that we 

 know something definite concerning the principles involved, 

 but in these days, and after twenty years of work of experi- 

 ment stations, we nuist assume that the farmer knows what 

 fertilizers are and something of their general usefulness. 



For example, I must assume that all farmers know that the 

 essential elements of fertility are nitrogen, phosphoric acid 

 and potash ; that lime is not classed with these constituents 

 because most soils do not need lime as an actual additional 

 constituent in the same sense, although it has many important 

 functions and bears a relation to profitable fertilization which 

 should not be ignored, and which we must, as far as possible, 

 understand. 



I assume, also, that farmers know that nitrogen is one of 

 the most important elements of plant food, and that in many 

 instances, particularly on lands that are not producing satis- 

 factory crops, the deficient element is more often nitrogen 

 than any other. Farmers also know that nitrogen is the most 

 expensive element of plant food ; it costs three times as much 

 as phosphoric acid and potash in mixed fertilizers, and differs 

 from the mineral elements in the sense that it is a very 

 elusive and unstable element existing in various compounds, 



