IRRIGATION EXPERIMENTS IN IDAHO. 57 
_ to those in south Idaho, where an allotment of less than this supply 
will be justified. It is believed, however, that the volume of water 
which will produce the maximum yield of crop on any certain variety 
of soil is in but few cases the proper and economic duty. It is very 
evident that the cost of the land, of water, the value of the crops 
produced, and the cost of producing them, as well as the volume of 
water which will produce the largest yield, must all be taken into 
consideration when determining the duty for any project. In many 
places the largest crop has been produced where the most water 
has been apphed, but the yield has been in but few cases propor- 
tional to the quantity of water used, and in view of this there is no 
- doubt that, broadly speaking, one would be justified in opening up a 
project with a higher duty of water where water is very valuable 
and land comparatively cheap than where land is high and water 
comparatively inexpensive. The determination of the proper supply 
of water for an-irrigation project is a very serious problem and one 
that must be given the most careful consideration, for it is fully as 
serious to err on the side of too little water as it is on the side of too 
much. If too little water is allotted, the farmers never can produce 
profitable crops and the lands never will reach their highest possible 
_— value, while if too much is allotted the ultimate irrigated area is not 
only cut down, but the excess supply is almost invariably used, 
resulting in the rapid water-logging and deterioration of the irrigated 
lands. | 
