DRY-FARMING ZONES 



in the long, hot days of summer; and, 

 consequently, much more sinks into the 

 ground. Moreover, recent experiments 

 have shown that when rain falls on warm, 

 dry ground it takes at least one fourth of 

 an inch to wet the top and to reach the 

 moist soil below, while on heavier lands 

 at least one half inch is needed to pene- 

 trate the hard, parched surface-soil. 



Furthermore, on a fine-textured soil 

 having a high water-holding capacity 

 slow rains and snow percolate deeply 

 during the cold winter months, and there 

 is but httle surface run-off. But in 

 places where the winters are dry and 

 severe and the ground is solidly frozen, 

 rainfalls in winter may be largely 

 wasted by surface run-off, and also by 

 evaporation before the ground has time 

 to thaw out in the spring ; while on poor 

 soUs of low water-holding capacity, rains 

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