384 _ DRY-FARMING 
cropping. All other dry-farm districts should take 
to heart this lesson, for, though crops may be pro- 
duced on fertile soils for one, two, or even three gener- 
ations without manuring, yet the time will come 
Fic. 102. Threshing in dry-farm district near Moscow, Idaho. 
when plant-food must be added to the soil in return 
for that which has been removed by the crops. 
Meanwhile, California offers, also, an excellent 
example of the possibility of successful dry-farming 
through long periods and under varying climatic 
conditions. In the Golden State dry-farming is a 
fully established practice; it has long since passed 
the experimental stage. 
Columbia River Basin 
The Columbia River Basin includes the state of 
Washington, most of Oregon, the northern and 
