26 
1st Irrig. 2nd Irrig. 
Wheat, Walter Campbell, 1892 . 6 6 
Wheat, J. H. McClelland, 1892.12 5 
Wheat, J. H. McClelland, 1892.. 6 4 
Oats, J. H. McClelland, 1892.12 7 
Clover, J. H. McClelland, 1892 . 6 7 
Alfalfa, J. H. McClelland, 1892. 6 4 
Alfalfa, J. H. McClelland, 1892. 6 6 
Potatoes, S. Hopkins, 1891.4.5 
Potatoes, S. A. Bradfield..6.4 
The measurements on potatoes were made on fields of 4 and 
7 acres respectively, forming parts of larger fields. 
A single irrigation may require from 4 to 12 inches of water 
•over the whole extent of the area irrigated. The number of irriga- • 
tions may be lessened by the rainfall, but very skillful management 
as well as perfect preparation of the ground is required to uniformly 
water a field with less than three inches in depth of water, even if 
in sod. It was not long since that 12 inches was considered the 
uniform practice in this valley; now six would probably be a bet¬ 
ter estimate when the measures are made at the entrance to the 
field. 
The ultimate duty reached by the individual will depend on 
the skill with which he can distribute the water, the small depth 
he can use and make a successful irrigation. As the application of 
water is generally followed by a temporary checking of the growth 
of the plant, most Colorado irrigators prefer to give thorough 
rather than many irrigations. The character of the soil is such as 
to retain moisture well. Hence the practice of Northern Italy and 
Southern France and adjacent countries where waterings are given 
two to four times per month, is rarely followed. 
As compared with the duty of water in other countries, that of 
Colorado is better than is generally supposed. The amount of water 
applied is in general far greater than with us. Irrigations are given 
more frequently, hut the land being prepared with greater care, the 
amount of water applied at one watering is generally less. 
The duty which is commonly stated in countries using the 
metric system is one litre per hectare, much as many people in the 
West are inclined to estimate the amount of water needed as “ an 
inch to the acre,” no matter whether the inch is large or small. One 
litre per hectare is equivalent to 70 acres per cubic foot per second. 
But as in most of these cases the water is running constantly, the 
amount of water used is more than is commonly applied under the 
same nominal rates of duty. On the Favour Canal system in Pied¬ 
mont, the association to the west of Sesia uses 136 cubic metres pe: 
second from all the government canals on 80,252 hectares, or at the 
rate of 41 acres per cubic foot per second. Much of this land ls 
sandy with gravelly sub-soil, and the crops irrigated are principaly 
grasses, with some rice. 
