No. 4.] COMMERCIAL PLANT FOOD. 85 



went to him for many years for formulas, and finally he had 

 the courage to make several. Of course the}' were not 

 based upon the analysis of the crop, for evidently he does 

 not believe in that, but what was his starting-point? Why 

 does he recommend two or three different grades, and 

 especially a fertilizer for seeding down? As a manufact- 

 urer, I do not care whether we take the plant, the air or 

 the soil as the standard, — only give us some standard. If 

 we are still in the dark, and the living plant is not a sure 

 guide, for Heaven's sake do not let us grope any longer. 

 The professor says, "Work from your soil." How many 

 of you possess any sure knowledge of the chemical con- 

 stituents in your soil? I have been at it for fifteen years 

 on my Barre farm, and yet I do not know what it contains 

 or does not contain. 



If you take the soil as a guide, the law of minimum comes 

 into play, and what is that law? To illustrate, the strength 

 of a chain is measured by its weakest link. The strength 

 of the soil is measured by the minimum quantity of any one 

 essential ingredient of plant food. You may have sufiicicnt 

 nitrogen and phosphoric acid in the soil, but lack potash, 

 and your crops will fail on that account. That is, the 

 l)otash may be the minimum quantity, and it is the mini- 

 mum amount of any one ingredient that controls the final 

 result. The crop tells you what it finds, not what is left in 

 the soil. It may have thrived b}' applying potash this year. 

 Next year you apply potash, but it fails because there was 

 not a sufiicient quantity of nitrogen. The plant tells you 

 what it finds, and not what is left. You do not feed the 

 stable in which the cows stand, but you feed the cows them- 

 selves, and vary their rations if they are making beef or 

 milk. As a matter of insurance, I believe in supplying 

 well-balanced, complete fertilizers, based upon the wants of 

 the crop. You may be applying an excess of some one 

 ingredient by this method, but the cost is small compared 

 with the loss of a crop. You have ploughed, planted, cul- 

 tivated, controlled every factor so far as you can ; and yet, 

 for the lack of a little nitrogen or potash which you might 

 have added, with little extra cost, your harvest is a failure. 

 Is this the course of the thrifty, prudent husbandman? 



