420 



FORESTRY AND IRRIGATION 



September 



Then again we understand that 

 plants only use the ascending or 

 capilary moisture, consequently the 

 ideal way of applying water is to 

 do so without shutting off the air, 

 or causing the soil to bake, which is 

 the result more or less if hooding 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 corrugation sys- 

 tem 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 applying water, at least 

 on this tract, or any other tract hav- 

 ing 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 outline, 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 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, so that the 

 water between the check boxes, when 

 raised to full height, will stand on a 

 level, the- excess water being al- 

 lowed 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 box- 

 es will supply from one to three cor- 

 rugations, depending upon the pres- 

 sure in the cross ditch and the length 

 of the corrugations. 



Four laths will make two or three 

 boxes, according to the length re- 

 quired. 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 

 enought boxes to furnish one for 

 each corrugation on a 40-acre field, 

 the field being cut into three sec- 

 tions. 



Boxes in the head ditch for the 

 section below control the drain wa- 

 ter 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 prop- 

 erly graded, irrigation is no longer 

 a task. Under this system, with a 

 regular head of water, irrigation be- 

 comes automatic. 



The condition of the soil on the 

 Twin Falls tract is such that it takes 

 about 12 hours to properly irrigate 

 a field in each secton, as above indi- 

 cated. On many so arranged farms, 

 irrigation is looked after twice a 

 day in the morning before work 

 commences, and in the evening after 

 work is over. 



It can readily be seen that irriga- 

 tion under the above system is not 



