What the 



Sciences 



Contribute 



of soil, it will return a million or ten million-fold in food for man 

 and beast. Thus it is obvious that living, growing crops, like 

 living, growing animals, must be supplied with food, either 

 from natural sources or by the skill of man. 



To aid in supplying the need of "plant food" is the reason 

 for the existence of the fertilizer industry — an industry which 

 is based on all the sciences that relate to soil and crop problems ; 

 on geology, which tells of the formation and composition of 

 soils; on chemistry, which shows the needs of crops and how 

 they can be supplied; on botany, which tells of the structure 

 of crops and habits of growth, and, finally, on bacteriology, a 

 comparatively new science, which tells of the soil bacteria, or 

 "yeast of the soil" — the 4ower orders of life, without which 

 crops cannot thrive. This latter science, which we are just 

 beginning to develop and understand, is completely overturn- 

 ing our preconceived notions of drainage, tillage and the rela- 

 tions of plant food ingredients to crops and soils. 



Thus it will be seen that the man who is carrying on the fer- 

 tilizer industry today and the farmer who is more or less depend- 

 ent on that industry for a part or all of his plant food must 

 each be more or less familiar with these subjects to meet the 

 needs of modern and successful farming. 



Analysis 

 of Soil 

 no Guide 



The Modern Idea of Plant Feeding 



It is admitted that fertility is the corner-stone of agricul- 

 ture, as agriculture is the corner-stone of all other industries. 

 Fertility — that is, available plant food — is what nature or man 

 prepares for plants which are now grown as food crops for the 

 support of humanity. 



Formerly the practice was to manure the soil in order to 

 restore lost fertility and to supply, by guesswork, deficiencies 

 in the soil, as ascertained by a chemical or a crop analysis of 

 the soil. This method is not now regarded as a practical solu- 

 tion of the problem, for neither chemical analysis nor the grow- 

 ing of crops can be relied upon as a true guide to its enrichment. 

 The chemical analysis of the soil discloses too much that is 

 misleading, and the growing, or even the matured crop, too 

 little that is conclusive. 



Modern practice teaches that it is not the soil, but the crop, 

 that we should first consider. In a word, we have turned from 



