30 BULLETIN 1340, TJ. S. DEPARTMENT OF AGRICULTURE 
ample capacity, it would be possible to prevent all but a negligible 
amount of the current losses. In a few cases large investments have 
been made in concrete linings for the more porous portions of main 
canals, but this procedure can not be generally recommended be- 
cause the lining of some canals might cost more than the water is 
worth. There are, however, other means of lessening the waste of 
water and bringing about a more economical use which do not in- 
volve much expense. 
The most important of these are: (1) The adoption of the most 
suitable method of irrigation; (2) proper preparation of the sur- 
face of fields; (3) the use of large heads and short runs in porous 
soils ; and (4) the application at any one time of no more water than 
the soil can retain against gravity within the root zone of plants. 
In respect to the first suggestion, care should be exercised to adopt 
a method of applying water that will best meet the conditions of 
water supply, soils, topography, and crops, and the farm ditches 
should be located and built in such a way as to conform to the method 
adopted. The proper preparation of the surface of fields is one of 
the necessary things in irrigation farming, since every attempt to 
spread water over a rough, uneven surface results in the waste of 
water, extra labor in applying it, reduced yields and profits, and, too 
frequently, damaged soil due to water-logging and the rise of alkali. 
An instance of the saving which may be effected in water and labor 
by the proper preparation of land is reported by R. W. Allen 7 , 
superintendent of the experiment farm at Umatilla, Oreg. Two ad- 
joining 10-acre tracts of alfalfa land of medium sandy soil, having 
similar topographic conditions, were irrigated by the same man with 
the same head of water. One tract was carefully prepared, whereas 
the other was rough and uneven. On the former an average depth of 
3% inches of water was applied at each watering, at a cost of $1.25 
for the tract, whereas on the latter 16.8 inches was applied at a 
cost of $5.90. 
Instances in which yields and profits have been reduced by over- 
irrigating the low parts of a field, although the high parts remained 
unwatered, are so common as to need little comment. Packard, in 
writing of alfalfa in Imperial Valley, Calif., 8 states that " the num- 
ber of cuttings and the yields secured from an established stand 
of alfalfa depend almost entirely upon the efficiency of irrigation," 
and this in turn depends upon how well the surface has been pre- 
pared for irrigation. 
In preparing land for irrigation, where the soil and subsoil are 
porous and absorb water readily, a common mistake is to run water 
too far from head ditches. The length of run should be short where 
excessive deep percolation is likely to occur. The effect of the length 
of run on the quantity of water applied, the time required for its 
application, and the crop yields on the porous, gravelly soils of the 
Snake River Valley, near Rigby, Idaho, was shown by experiments 
conducted by the Bureau of Public Roads, in cooperation with the 
State Land Board of Idaho, during the seasons of 1910 1911, and 
1912. 
7 Circular 3, Umatilla (Orcp:.) Branch Experiment Station. 
8 IrriTation of Alfalfa in Imperial Valley, by Walter E. Packard, in Bulletin 2S4, 
University of California. 
