FERTILIZING AND FERTILIZERS 



child or a bird or anything else in creation requires it. 

 But the ideas about this food are very vague; ^^what 

 plants eat" is an untold tale, mysterious, almost 

 chimerical to the practical mind accustomed to seeing 

 before believing. Let us see if we cannot straighten 

 this out a nttle and come to a real comprehension of 

 plant feeding; then fertilizers will not seem so deadly 

 dull and uninteresting — and incomprehensible. 



The food of plants consists of thirteen ^'chemical 

 elements." Nine of these are taken by the plant 

 directly from the soil — these are the pure mineral plant 

 foods — three are taken from water and from air, and 

 the thirteenth and last is taken principally from decay- 

 ing organic matter in the soil. 



In order to understand this quite clearly let us 

 stop just here long enough to take a look at the chemi- 

 cal classification of the soil, spoken of in a previous 

 chapter. Soil is made up of mineral matter and 

 organic matter — two forms that are, of course, widely 

 different — and to get at this composition of it in the 

 simplest way possible we will follow the suggestion 

 of one of the Department of Agriculture experts and 

 magnify a cubic inch of soil, in the imagination, to a 

 cubic mile — and then look it over. It becomes very 

 vivid, and the processes going on in it are plainly 

 revealed, imder such an examination. 



It will look like a mass of rocks and stones vary- 

 ing from the size of a pea to boulders several feet in 

 diameter. These are the mineral particles — ^in com- 

 mon parlance the "dirt" — which predominate and 



85 



