CHAPTER VIII 



TILLAGE AND ITS PURPOSES 



DEEP breaking of the soil is necessary for the full 

 I development and extension of the roots of plants 

 in the soil. Those who have never investigated 

 the great extension of the roots of our cultivated plants 

 can hardly reaHze how widely they ramble under favorable 

 conditions, or how great the need is for this extension, if 

 the best results are to be had in the crop. 



Deep breaking admits the air to the roots, and air, with 

 its oxygen, is essential to plant growth in the soil. Unless 

 the soil is permeated by the oxygen there can be no activity 

 in the roots of plants. Anything that shuts out the air 

 from the soil checks plant growth. 



Standing water in the soil shuts out air 



Moisture ^^^ prevents the growth of our upland 



Needed for . ^ . . ,, . ., 



Growth plants, but moisture adhermg to every soil 



particle is necessary. Few realize the great 



amount of water that our growing crops take from the 



soil. Professor King, in his work on the soil, shows that 



an acre of corn, planted three feet eight inches apart each 



way and with four stalks in a hill, will withdraw from 



the soil in thirteen days 244 tons of water, and that, 



too, from a soil so dry that no amount of pressure could 



squeeze out a drop of water from it. Hence a very wide 



extension of the roots is needed to do this work so 



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