40 



THE IRRIGATION AGE. 



tion began in May and up to the date of this article 

 the irrigation plant has been ready to go to work 

 supplying all water needed for irrigation, at any 

 hour, and there has been no delay nor any expense 

 for repairs of any kind. 



For the season of 1915, practically no repairs 

 have been made on the plant. As this season's data 

 are not at present worked out in entirely available 

 form, the cost of pumping is taken to be $5.00 per 

 acre-foot, although in reality the cost has been much 

 reduced. 



The cost of spread water is figured at 70c per 

 acre per acre-foot of water. 



The field carrying capacity of the soil at the 

 Experiment Station, this being a silt loam, has been 

 determined by experiments to be approximately 30 



inches of water for the upper 10 feet of soil. The 

 minimum point to which this water can be reduced 

 by the growing crop is about 22 inches for the 

 upper 10 feet of soil. The amount of water used 

 by the various forage crops is from 10 to 15 inches. 

 Hence with an average yearly precipitation since 

 1897 of 20 inches, it is judged that 12 inches of 

 water applied in irrigation is sufficient to supple- 

 ment the rainfall in normal years in producing the 

 general field crops. As alfalfa produces four crops 

 during a season it naturally requires more water. 



The roots of field crops penetrate to a depth of 

 8 feet as determined in field moisture sampling and 

 in isolating root systems. They may penetrate 

 deeper than this and probably draw moisture from 

 the upper 10 feet of soil. 



CONCRETE STANDARDIZING BOX AT THE DAVIS 

 FIELD LABORATORY, BERKELEY, CALIFORNIA 



/CONCRETE standardizing box 30 feet long, 9 

 *<-^ feet wide, and 6 feet deep (all inside measure- 

 ments) with partition 12.75 feet from the upper 

 end containing an opening 5 feet wide, 1 foot 

 above the bottom of the box, a similar opening 5 

 feet wide having been left in the lower end of 

 the box. These openings are so equipped that 

 weirs or orifices of desired sizes can be set in 

 them, making it possible to use either a standard 

 weir or a standard orifice in testing the various 

 devices. Water from the reservoir is brought 

 into the box with a downward flow into a slightly 

 suppressed pool and must pass from the pool 

 over a bulkhead 12 inches high and through a 

 baffle before reaching the weir or orifice set in 

 the opening in the partition already referred to. 

 Four pieces of 4-inch channel iron 9 feet long are 

 set directly below the baffle board and when de- 

 sired furnish a spill with an aggregate length of 

 72 feet for aiding in keeping a constant head 

 over the standard weir or orifice. 



When planning the installation this was con- 

 sidered a necessary part of the control on ac- 

 count of the water supply from the reservoir being 

 fed to the standardizing box under a diminishing 

 head. The channel-iron spills all discharge through 

 a 6-inch iron pipe into a well on the side of the main 

 box out of which water spilled can be measured 

 through a circular orifice of any necessary size. 



In the tests thus far made this spilling device 

 has not been used because it has not been found 

 necessary to maintain an exactly constant flow dur- 

 ing the tests. The elevation of the bottom of this 

 box is 90.6 feet above datum. 



Western Canada Irrigation Congress Calls for 

 More Surveys 



The irrigation undertakings of the Canadian 

 Pacific Railway were under discussion at the ninth 

 annual convention of the Western Canada Irriga- 

 tion Association, which was held at Bassano, Al- 

 berta, the center of the eastern section of the C. P. 

 R. Irrigation Block, on November 23, 24 and 25. 

 The convention aroused widespread interest and 

 about 180 delegates, principally from irrigated dis- 

 tricts of Alberta and British Columbia, were pres- 

 ent. 



A resolution was passed asking the Dominion 

 government to diligently proceed with irrigation 



surveys east and west of Lethbridge in order that 

 these farming communities might "avail themselves 

 of the benefits of irrigation without delay." The 

 Dominion and provincial departments of agriculture 

 of Alberta and Saskatchewan were petitioned to 

 initiate a widespread system of popular co-operative 

 experiments with alfalfa on the basis of supplying 

 to such farms as have available well prepared and 

 otherwise suitable areas under irrigation. The con- 

 vention also requested that a well directed and en- 

 ergetic educational propaganda be initiated by the 

 departments of agriculture to convince settlers on 

 irrigated lands generally that the only road to com- 

 (Continued on page 43) 



