4 
The Colorado Experiment Station 
the possibilities and difficulties to be met, and some of the means 
necessary for the successful development of this great unoccupied 
domain. 
What Dry Farming Is .—Dry farming, as commonly under¬ 
stood, means the production of crops without irrigation, in a re¬ 
gion where the rainfall lies between the approximate limits of 
10 to 20 inches per annum. If the rainfall is much less than 10 
inches, the type of farming becomes arid, and when the rainfall 
lies much above 20 inches, the type of farming followed falls in 
the class of humid farming. 
Successful dry farming depends upon the proper adaptation 
of crops, the finding of the principles of water movement in the 
Swales and bottom lands in dry regions may often be used to produce 
alfalfa 
soil, and an understanding of the principles of moisture conser¬ 
vation and what practical methods of plowing and other cultiva¬ 
tion must be followed to get paying results. Most new settlers in 
Colorado dry-farming sections have attempted to gain success by 
grain farming. Long experience has shown that a permanent ag¬ 
riculture may be built up in dry-farming sections only where a 
diversified system of farming is followed. This means a variety 
of crops, combining cash crops, feed and forage crops, with a 
properly balanced amount of livestock. 
TYPES OF PRECIPITATION 
Any discussion of dry farming must consider the time when 
rain falls, as well as the amount which falls. In different dry- 
