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 14 
show some of the characteristic features of dry- 
farming regions. 
