CHAPTER XVIII 



THE AFTER-CULTIVATION OF CROPS 



THE term " after-cultivation " is here used in re- 

 ferring to those tillage operations which are per- 

 formed after the crop is planted. Synonymous 

 terms are " cultivation," " inter-tillage," " working 

 the crop." 



After-cultivation influences the texture, ventila- 

 tion, heat, plant food and moisture factors of fer- 

 tility, but most particularly the moisture factor. 



Under ordinary circumstances the greatest benefit 

 derived from after-cultivation when properly per- 

 formed is the saving of soil water for the use of 

 the crop. 



LOSS OF WATER BY EVAPORATION 



Soil water is seldom at rest unless the soil be 

 frozen solid. When rain falls on a fertile soil there 

 is a downward movement of water. When the rain 

 ceases, water begins to evaporate from the surface 

 of the soil. Its place is taken by water brought 

 from below by capillarity. This is in turn evapor- 

 ated and replaced by more from below. This proc- 

 ess continues with greater or less rapidity according 

 to the dryness of the air and the compactness of 

 the soil. 



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