CONSERVATION OF SOIL MOISTURE 



enough to possess a considerable lifting 

 surface, and yet not so fine as to inter- 

 fere with the free movement of soil water. 

 The western soils which American wri- 

 ters describe as capable of withstanding 

 an unbroken summer drought of three 

 months' duration are deep, fine-grained, 

 and uniform, with practically no par- 

 ticles of the clay order of magnitude to 

 check the upward hft by capillarity." In 

 many portions of the semi-arid West a 

 most casual examination will reveal two 

 types of soil from an agricultural stand- 

 point. The one may be characterized as 

 a shallow, sandy soil, one to three feet in 

 depth, resting upon a gravel sub-soil; 

 while the other is a deep uniform loam 

 from ten to thirty feet in depth. It need 

 hardly be said that the second soil — the 

 deep loam — will remain practically un- 

 affected in dry weather, while plants on 

 the shallow soil are wilting, parched, and 

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