DRY-FARMING 



standing water, should be as near as three 

 feet from the surface of the soil, whereas 

 the shallower-rooting cereals may be suc- 

 cessfully grown with a water-level of this 

 depth. But in no case should free water 

 come within eighteen inches of the sur- 

 face. Tap-rooted plants descend to an 

 extraordinary depth in sandy loams, and 

 for such crops a high permanent water- 

 level is not good, since they can obtain 

 their moisture supply at great depths and 

 demand a feeding area vast in compari- 

 son with the soil mass at the service of 

 shallow-rooted herbs. Thus lucerne roots 

 frequently penetrate to the depth of 

 twenty feet, and double this distance is 

 not unknown. 



Film Water or Capillary Water. 



But the most valuable water in the 

 soil and, at the same time, the most im- 

 portant for the dry-land farmer, is that 

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