62 



40 inches in a season. There are other portions where water is so 

 cheap and plentiful that the owners are careless in its use. They open 

 the head g'ates and permit a large stream to flow^ for days at a time 

 witliout much, if any, attention. Men who use large quantities of 

 water, covering- their fields to depths of from 4 to 10 feet every season, 

 are usually the most careless in preparing the land or in cultivating 

 the sui-f ace, and the result is^ without exception a small yield. 



That yields do not depend wholly on the amount of water applied 

 is clearly shown by figure 6. This diagram shows the amount of rain- 

 fall and irrigation water received by eight oat fields, with the corre- 

 sponding yields. The lower half of the diagram shows the depth of 

 water received and the upper half the yields on corresponding tracts, 

 A field which received over 6 feet of water in two irrigations produced 

 only 37 bushels per acre, while a field which received in one watering 

 less than 7 inches produced 75.5 bushels. The largest yield was 80i 

 bushels per acre from a field which received 1.04 feet of irrigation 

 water and 0.()4 foot of rain water. 



In figure 7 are shown like results on eight fields of barley. There are 

 no large amounts of water used, all being less than 30 inches in depth. 

 Still, the largest yield was not obtained from the use of the most 

 water, which was 1.98 feet of irrigation water and 0.42 foot of rain, 

 or 2.40 in all. A yield of 87.25 bushels was harvested from the field 

 which received less than 18 inches in both rain and ditch water. 



The results of six wheat crops shown in figure 8 indicate that the 

 amounts of water used ranged from a small to a medium amount and 

 that the yields varied to some extent with the water applied. 



Figure 9 shows yields of clover and the quantities of water applied 

 to nine clover fields. In this crop the largest yield was from the 

 heaviest watering, Init, on the other hand, the next largest use of water 

 produced a small crop. 



In'comp-aring records of thirty-two irrigated fields, as given in the 

 diagrams, the conditions under which the crops were grown should 

 be considered. It is important to remember that the crops were 

 grown in different seasons, in different parts of the State, and in many 

 cases under a wide diversity of soil and climate. In view of this fact, 

 the records as given should not be used to base conclusions as to the 

 proper amount of water to use in the raising of these staple crops. 

 They do show, however, that when other conditions are favorable it is 

 possible to obtain a large crop with a small amount of water. 



UNITS OF MEASUREMENT. 



In the measurements of duty of water reported in the subsequent 

 pages several units are employed to state the quantities of water used. 

 The irrigators generally use the term miner's inch, being unfamiliar 

 with the term cubic foot per second. As it is impracticable to 



