PURPOSE OF DRY-FARMING 5 



desert" areas of the world, which until recently were 

 considered hopelessly barren. The great underlying 

 principles of agriculture are the same the world over, 

 yet the emphasis to be placed on the different agri- 

 cultural theories and practices must be shifted in 

 accordance with regional conditions. The agricul- 

 tural problem of first importance in humid regions 

 is the maintenance of soil fertility ; and since modern 

 agriculture was developed almost wholly under 

 humid conditions, the system of scientific agricul- 

 ture has for its central idea the maintenance of soil 

 fertility. In arid regions, on the other hand, the 

 conservation of the natural water precipitation for 

 crop production is the important problem; and a 

 new system of agriculture must therefore be con- 

 structed, on the basis of the old principles, but with 

 the conservation of the natural precipitation as the 

 central idea. The system of dry-farming must 

 marshal and organize all the established facts of 

 science for the better utilization, in plant growth, of 

 a limited rainfall. The excellent teachings of humid 

 agriculture respecting the maintenance of soil fer- 

 tility will be of high value in the development of 

 dry-farming, and the firm establishment of right 

 methods of conserving and using the natural pre- 

 cipitation will undoubtedly have a beneficial effect 

 upon the practice of humid agriculture. Figures 1-4 

 show some of the characteristic features of dry- 

 farming regions. 



