TWENTY-SECOND CHAPTER. 



THE NEEDS OF SOIL AND CROP. 



A FTER the perusal of the preceding chapters, the 

 reader will have come to the conclusion that 

 the purchase of fertilizers is nothing more nor less 

 than the purchase of a more or less definite number 

 of pounds of nitrogen, phosphoric acid and potash. 

 The information already given may assist him in 

 buying these articles economically; but this is not 

 sufficient Economical buying should be followed 

 by judicious, economical use; for the application of 

 manures on the hit-or-miss plan is seldom profitable. 

 Time and time again I have been asked to name 

 the best manure for this or that crop, and the proper 

 quantity of it to be used per acre. Such questions 

 always place a person in the position of the physi- 

 cian who is called on to prescribe for a sick man 

 without a chance to see him, or to ascertain his true 

 condition by asking him questions, or taking his 

 pulse or temperature. A careful diagnosis should 

 be made before a course of treatment can properly 

 be decided upon. And so it is with the soil. We 

 must try to discover what ails it, before we can 

 apply manures intelligently and economically. A 

 reliable soil diagnosis can not possibly be made 

 from a distance, and without knowing all the par- 



