Why, they ask, will my land not grow wheat, 

 when it grows corn to perfection, or vice versa ? 

 The}'- invariably send samples of soil as the 

 key to the riddle. Here it is not a question of 

 soil, but of climate, seasonal rainfall. Large 

 areas in the Great Plains regions are sus- 

 ceptible to winter wheat culture, when spring 

 wheat would prove an absolute failure, and 

 vice versa, merely because of this factor of 

 seasonal rainfall. But the pioneer in those 

 sections cannot answer those questions for him- 

 self until he is in possession of all the facts 

 affecting his acre. As the American farmer 

 gradually comes into possession of this knowl- 

 edge, and applies it, the productiveness of his 

 acres automatically increases without a cor- 

 responding increase in the expenditure of 

 labor and capital. 



The first consideration determining the 

 proper agricultural use of soils is climate. 



Professor Milton Whitney, chief of the 

 Bureau of Soils, Department of Agriculture, 

 sums up this factor as follows (Bulletin 55, 

 Bureau of Soils) : 



"The climate of continental United States 

 varies greatly, probably much more than is 

 generally realized. In the southwest we have 



