CHAPTER V . 



THE SOIL 



"Fill a flower-pot with soft, dark earth and mold from the border 

 of the wood, and carry it to the student of entomology and see if he 

 can name one-half of the living forms of this little kingdom of life; or 

 hand it to the botanist, well trained in the lower orders of plants, and 

 see how many of the living forms which these few handfuls of dirt 

 contain he can classify. Present this miniature farm to the chemist 

 and the physicist, and let them puzzle over it. Call in the farmer, and 

 ask him what plants will thrive best in it; or keep the soil warm and 

 moist for a time, and have the gardener say of the tiny plants that 

 appear as by magic, which are good and which are bad. Mark what 

 all these experts have said, and call in the orchardist to tell you how 

 to change dead, lifeless, despised earth into fruit; ask the physiologist 

 to explain how sodden earth is transformed into nerve and brain." 1 



73. What Soil Is. Many persons look upon soil as "dirt" 

 something to be avoided. It is almost invariably thought 

 of as a dead thing; but it is teeming with life, and is full 

 of activities of the most complex and interesting kinds. 



The almost universal idea of soil is that it is a collec- 

 tion of small particles of rock that have been made fine 

 by the process of weathering. Many books give this as 

 the origin of soil. No crop could grow on a soil composed 

 entirely of rock particles. An agricultural soil is made 

 up of: 



(1) Small rock particles. 



(2) Soil water. 



(3) Soil air. 



'Roberts' "The Fertility of the Land," p. 1. 

 (75) 



