IIMJKIA TION 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 applied, 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. 



