THE IRRIGATION AGE. 



387 



crops, we can have some idea of the amount of water 

 actually required. 



No doubt if less water had been applied, the re- 

 sults, as far as the crop production is concerned, would 

 have been the same or greater, as was indicated by some 

 tests made by Mr. Nelson, showing that the third foot 

 of soil lost much less moisture in a given time than 

 the first or second foot. The roots of certain crops 

 penetrate to a depth where they would be able to draw 

 upon the moisture to a greater depth than the shallow 

 rooted ones. 



If all the crops grown had been of the kind that 

 could have been cultivated, thus conserving the moist- 

 ure, I am sure much less water would have been 

 required. 



Taking the four months, or 122 days, as the irri- 

 gating season, we used water twenty-four days and nine 

 hours in May, twenty-six days in June, twenty-two 

 days and nine hours in July, and twenty-three days and 

 three hours in August, leaving twenty-six days and 

 four hours during the irrigating season when water 

 was not used. 



These results show that one-eightieth of a cubic 

 foot per second continuous flow is more than necessary 

 at Twin Falls, where the soil is very deep. 



I believe if the land were given a thorough irri- 

 gation late in the fall, thus storing the moisture in the 

 soil for use the following year, it would be a great 

 saving of time and labor, and materially lessen the 

 amount of water used during the irrigating season, 

 besides being more economical, and as the surrounding 

 areas become moistened through irrigation, with proper 

 cultural methods, less and less water will be necessary 

 each year until half the amount used this year will be 

 sufficient. 



Just what the duty of water will be on the Twin 

 Falls tract a few years hence, I am unable to say, but 

 I believe that it will be far greater than now, as the 

 people are becoming educated in the use of water, and 

 find that less water and more attention to the soil give 

 greater and more beneficial results. This fact was 

 demonstrated this year on a portion of the experiment 

 farm, where last fall it was irrigated late, and only 

 one irrigation was required this season to produce sev- 

 enty bushels of wheat to the acre and ninety-six bushels 

 of oats. 



THE BEST METHOD OF APPLYING WATER. 



The character of the soil and the lay of the land 

 should indicate the best method of applying water. 



Two* methods have been tried on the Twin Falls 

 tract flooding, and by furrows or corrugations. After 

 a thorough trial, the corrugation method has been given 

 the preference, and fully 90 per cent of the farmers 

 have adopted this method. 



I believe that it is the better of the two, especially 

 when annual crops are grown, such as grain. While 

 it is true that some others claim that the duty of 

 water is greater by flooding than by corrugation, that 

 has- not been my experience in the portion of the arid 

 district where I am located. 



As it is understood that water only goes into the 

 soil under pressure, and that plants practically stop 

 growing when the air is excluded, which is done by 

 flooding, this is objectionable. 



Then again we understand that plants only use 

 the ascending water, or capillary moisture, consequently 



the ideal way of applying water is to do so without shut- 

 ting off the air, or causing the soil to bake, which is 

 the result more or less if flooding is followed in this 

 section. 



This is especially true of nearly all crops excepting 

 grasses. 



Then, again, water is more easily applied by the 

 corrugation method than by flooding, and if the corru- 

 gation system is properly constructed, water can be 

 applied, so that it will run night and day with less labor 

 or care, and with comparatively none, if any, damage to 

 the land. 



I consider the corrugation method the best for ap- 

 plying water, at least, on this tract, or any other tract 

 having the same conditions. 



I will try to describe the system I have advocated 

 to the farmers on this tract the great portion of whom 

 have followed the advice given: 



First, the land is graded, so that the water will 

 not be turned from its .course in the corrugations by 

 the high places. It is not necessary to have a perfect 

 incline, but there should always, necessarily, be fall 

 enough so it will continue on its course. 



We then run the corrugations or small furrows two 

 feet apart in the direction in which the water is in- 

 tended to flow. Cross ditches are then run at right 

 angles with the corrugations from 300 feet to 500 feet 

 apart, according to the grade or fall of the land. 

 Check boxes are put in each cross ditch, the distance 

 apart being governed by the fall of the land. The 

 sharper the pitch, the more check will be necessary. 

 The nearer level the supply ditch is, the less boxes will 

 be required, and within a reasonable limit, will carry 

 sufficient water to irrigate the land intended. 



Check boxes are so constructed that the water will 

 flow over and not under the splash boards. The water 

 is raised by these splash boards as high as needed, BO 

 that the water between the check boxes, when raised to 

 full height, will stand on a level, the excess water being 

 allowed to go over the splash boards, and be caught up 

 by another check box. 



To divert the water from the cross ditches into 

 the corrugations, lath boxes are used each of these 

 boxes will supply from one to three corrugations, de- 

 pending upon the pressure in the cross ditch, and the 

 length of the corrugations. 



Four laths will make two or three boxes, according 

 to the length required. The laths are simply nailed 

 together in the form of a square, and cut into two or 

 three sections, as the case may require. The boxes 

 are then placed in the bank of the ditch, the top of 

 the lath box being a little below the level line of 

 water, so all will receive the same pressure, and flow 

 steadily night and day. If they are kept clear, they 

 will remain in position for service indefinitely. 



Three thousand laths will make enough boxes to 

 furnish one for each corrugation on a forty-acre field 

 the field being cut into three sections. 



Boxes in the head ditch for the section below con- 

 trol the drain water from the section above, so that all 

 drain water is picked up, and re-distributed further on 

 down the field. 



When check boxes and lath boxes are set in place, 

 the land being properly graded, irrigation is no longer 

 a task. Under this system, with a regular head of 

 water, irrigation becomes automatic. 



The condition of the soil on the Twin Falls tract 



