DRY-FARMING 



the later colonists have pushed cultiva- 

 tion into the dry central region and are 

 producing crops without the aid of ir- 

 rigation. From the earliest settlements 

 cereal crops have been grown almost 

 exclusively in this region. True, alfalfa, 

 timothy, corn, potatoes, and fruit are 

 now produced in many parts of the coun- 

 try. Yet they all sink into insignificance 

 in comparison with the grains more 

 especially wheat. 



Tillage. 



In the Columbia Basin, where the 

 rainfall is light, wheat is grown every 

 other year alternating with the summer 

 fallow; where the rainfall is ample crops 

 are grown every year. Three reasons are 

 usually given in support of summer-fal- 

 lowing in this region: (a) To conserve 

 moisture. A large amount of wheat 

 being grown with an annual rainfall of 

 200 



