286 THE FARMER OF TO-MORROW 



reserve that it took a greedy nation of pioneers 

 a generation or two to break down the power 

 of the soil to recover itself with the natural 

 rest of the seasons. Corn followed corn, wheat 

 followed wheat in the fifty years following the 

 opening of the West to settlement. Crop 

 yields began to decline eventually, and the 

 careless farmer, content with the theory that 

 Nature had been parsimonious with the min- 

 eral ingredients, turned to the fertilizer bag. 

 The fact that chemical fertilizers act as a tonic 

 to tired soils was sufficient proof to the far- 

 mer in the field that the theory of Liebig was 

 right. 



Crop rotation was forced on our farmers 

 only when weeds, driven from their happy 

 hunting grounds by the plow, returned and 

 adapted themselves to the new conditions and 

 reproduced themselves in profusion. When a 

 farmer's oat field became so foul that the weeds 

 clogged his machinery, the farmer plowed his 

 oat field and put in corn. There was no other 

 rationale behind the process so far as he was 

 concerned. Even to-day nine-tenths of our 

 wheat comes from single-cropped acres. In 

 the Dakotas, among the "jumbo" wheat 

 ranches, it is customary to give the soil a year's 



