26 Soiling. 



the fifteen elements that constitute the vegetable al- 

 phabet; to spell wheat, let us represent these five 

 elements by five letters of our alphabet, as W, H, 

 E, A, T. 



If any one of these letters or the elements which 

 they represent are missing in the soil, the combina- 

 tion is incomplete, nature fails to spell the word, and 

 our crop is a failure. 



How is a farmer to know which one of the letters 

 is missing? By analyzing the soil. Yes, but how 

 many farmers are in a position to do this? Besides, 

 it must be done not only with each succeeding crop, 

 but in different fields for the same crop. You say 

 this is impossible. Certainly it is. Even if it were 

 possible, the analysis of a soil is little or no criterion 

 as to its ability to produce a crop. It may show by 

 analysis that a certain soil is abundantly supplied 

 with all the elements necessary to produce a crop of 

 wheat, and still the land be unable to grow wheat, 

 because, although the soil contains all the elements, 

 one or more of them (though in great quantities) 

 may be in an insoluble state, so that they are not 

 available to the plants. Therefore, even if analyz- 

 ing the soil were practicable, it does not tell what 

 we want to know. 



The application of complete fertilizers is a step in 

 advance, because if the soil is supplied with all the 

 elements necessary to produce a crop, one is more 

 certain that the missing or deficient letter or ele- 

 ment will be supplied. 



We will say in the case of growing a crop of wheat 



