284 DRY-FARMING 



to-day than they did a generation ago. Strangely 

 enough, this is not true of the irrigated farms, operat- 

 ing under lilce soil and climatic conditions. This 

 behavior of crop, production under dry-farm condi- 

 tions has led to the belief that the question of soil- 

 fertility is not an important one to dry-farmers. 

 Nevertheless, if our pn^sent theories of plant nutri- 

 tion are correct, it is also true that, if continuous 

 cropping is ])racticed (jn our dry-farm soils without 

 some form of manuring, the time must come when 

 the productive power of the S(jils will be injured and 

 the only recourse of the farmer will be to return to the 

 soils some of the plant-food taken from it. 



The view that soil fertility is not diminished by 

 dry-farming appears at first sight to be strengthened 

 by the results obtained by investigators who have 

 made determinations of the actual plant-food in 

 soils that have long been dr3'-farmed. The sparsely 

 settled condition of the dry-farm territory furnishes 

 as yet an excellent opjjortunit}' to compare virgin 

 and dry-farmed lands and which frequently may be 

 found side by side in even the older dry-farm sections. 

 Stewart found that Utah dr}^-farm soils, cultivated 

 for fifteen to forty }'ears and never manured, were 

 in many cases richer in nitrogen than neighboring 

 virgin lands. Bradley found that the soils of the 

 great dry-farm wheat belt of Eastern Oregon con- 

 tained, after having been farmed for a quarter of a 

 century, practically as much nitrogen as the adjoin- 



