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THE IBRIGATION AGE. 



The Art of Irrigation 



THE FIRST MISTAKE 



By T. S. VAN DYKE 



About all you know at first about irrigation is 

 that it will cost too much to imitate rain. From which 

 you quickly drift to the conclusion that the next best 

 plan is to cover the ground with a sheet of water. 

 You have a piece that looks very level and turn on a 

 stream. But instead of spreading out it slides off to 

 one side, or collects in little pools with sloughs be- 

 tween. Or it may dish in the center cut, or from a 

 ridge and slide off both sides. In any case it is likely 

 to leave many dry spots and their combined area will 

 probably be too great to be ignored. Three solutions 

 soon suggest themselves. 



First to keep the water on long enough to allow 

 the dry places to get wet by water soaking to the 

 sides from the wet spots. If the dry spots are small 

 and you are merely testing the fertility of the soil or 

 in haste to get a few radishes or something of little 

 value this may be the least objectionable of the three 

 for it may not have the water too deep or muddy un- 

 less you purposely make it so. 



Number two, a special favorite with most tyros, 

 consists in shoveling off the bumps while the water is 

 running and throwing the loose dirt into the water in 

 the low places. When the water goes down you find 

 your uneven shoveling has tripled the number of bumps, 

 and though none are as high as before they are still 

 high enough in spite of the fact that you have raised 

 the low places. And in the low places you have doubled 

 or tripled the thickness of the paste that will bake under 

 the hot sun and which, without your filling, would have 

 been thick enough to stop many kinds of seed and 

 sicken most of the plants that were strong enough to 

 push through it. 



Number three is a very choice method devised by 

 those who discover the bad features of the other two. 

 It is simply throwing up a levee around the piece high 

 enough to raise water over all the high spots. You find 

 it would not pay to shovel them off on a tract of any 

 size even if you could do it and also that increasing 

 the quantity of water merely makes it cut more in the 

 low places. The obvious thing is to back it up so as 

 to cover. This is the origin of the "check" system, one 

 of the leading systems of the world and one quite in- 

 dispensable for many kinds of work. They are called 

 "basins" by some; "borders" from the levees by others; 

 "plots," "pans," etc., but "check" is the most common 

 in all sections. "Basin" really belongs to a modified 

 form in which only a part of the ground is wet instead 

 of the whole. 



Divide the engraving herewith into four equal 

 parts with a line through the middle each way. It is 

 from a check full of alfalfa and oats planted October 

 15, 1907, with oats ready to cut April 1, 1908, for 

 hay. The lower right hand quarter and part of the 

 lower left show the ruinous effect of flooding, temporary 

 in the case of the alfalfa which will outgrow it and 

 make a heavy stand in summer. But the oats while 



struggling to overcome it can not get out in time to 

 amount to anything before hot weather. 



On the left, both above and below, both oats and 

 alfalfa, for some reason hard to understand, are coming 

 out in good shape though only twenty days before they 

 were as bad as those in the right foreground. The 

 soil and all other conditions seem exactly the same, and, 

 as the check is level on the bottom, the water was the 

 same depth. 



The upper right hand quarter shows the oats on 

 the levee which are four feet high very thick and in- 

 dicate a crop of fifty bushels per acre if allowed to 

 stand for grain. The levee is about twenty inches high 

 and ten to twelve feet at base. The line of flooding 

 shows plainly at the base where the oats run out to 

 nothing. One would at first suppose this was due to 

 the levee being made of top soil scraped from the bot- 

 tom. But there are fifty-six checks like this in this 

 tract and the same flooding line is just as plain every- 

 where on all of them. It seems plainly due to the 

 packing of the soil, but that is not all of it. Next fall 

 when the alfalfa covers the whole ground so as to shade 

 the young oats from the hot sun I will drill this again 

 with oats right in the alfalfa and where the ground is 

 now so bare the oats in spring will be as large as on 

 the levee now. I am not guessing at this for I have 

 done it several times. 



A Check of Alfalfa Partly Ruined by Flooding. 



About four-fifths of the whole tract is damaged 

 like this foreground, but in spite of that flooding is 

 the proper method as will be explained later. 



Your selection of method number three may be 

 very bad as many plants cannot endure it no matter 

 how well done. Put assuming your choice all right you 

 are quite certain to have grief in its details. The 

 temptation to make the levee out of wet mud instead 

 of waiting for the soil to dry after your first failure 

 is quite irresistible when you are in haste to see some- 

 thing green or get a bite of fresh vegetables. On many 

 soils such levees melt like mush when the water gets 

 a few inches deep and nearly all your attempts to re- 

 pair them result only in more mush, more muddy water 

 to form a paste inside, and final breaking in spite of 

 you when the water is high enough. 



If you wait and make them of dry soil you are 

 quite apt to make them too thin, too loose with weeds, 

 sticks and grass that may lead a small thread of water 

 through, and so low that if the check is of any size 

 the waves from the first wind will breach it. If your 

 ground is so flat that a low, flimsy levee will suffice to 

 hold water long it will probably mean that your ground 

 generally is too flat for easy drainage and that the 

 building of proper drainage ditches should precede any 

 irrigation. For on many soils and for many plants 



