FOR BETTER CROPS IN THE SOUTH 91 



which the air circulates still further, encouraging and support- 

 ing bacterial growth, which is absolutely necessary in order to 

 convert vegetable matter and humus of the soil into available 

 plant food. The combining of the elements and gases of the 

 air with soil moisture creates conditions which encourage 

 chemical action, thus liberating many plant food elements 

 from the insoluble and inert particles of soil. 



Tile drainage in reality establishes what might be termed a 



Dry Land 



« 



02 



<* 



4, 



J& 

 *& 



<& 



<y 



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*Fi$. 1. The natural system 



reservoir, which offsets the effect of the unusually heavy rains 

 by permitting the water to soak into the soil instead of running 

 off the surface. As this water finds its way down through the 

 soil to the tile drain below it carries with it the gases of the 

 air, thus tending to deepen the soil and to improve it as the 

 home of the plant. 



Reduces Erosion and Improves the Soil — In sections 

 where the rainfall is unusually heavy, one of the problems is to 

 prevent soil erosion, or the wasting away of the surface by 



