CHAPTER I 



THE NORMAL SOIL AND ITS REQUIREMENTS 



THE aim of this chapter is to study the conditions 

 under which a healthy plant lives and grows. Such 

 knowledge will prepare us to consider the causes or 

 factors which are responsible for abnormalities and 

 diseases. Plants are endowed with life, and to live 

 they must have food. Part of the. food is derived 

 from the air, but they cannot subsist on air alone. 

 The sustenance of plants is also derived from the 

 soil. 



It is to be regretted that laymen often regard the 

 soil as merely a conglomeration of inert particles of 

 dead rock. If this were true, plant life would be an 

 impossibility. It is because soils are teeming with 

 various forms of organisms beneficial to them that 

 plant life is made possible therein. The science of 

 Soil Bacteriology, though still in its infancy, has 

 already taught us much to help make the trucking 

 business much more profitable and successful than 

 it has been hitherto. 



Indeed we may judge a soil by the kind of flora 

 which predominates there, and call it fertile and 

 healthy when this germ life helps to make it a f avor- 



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