THE IRRIGATION AGE. 



247 



The Drainage Journal Department 



DRAINAGE FOR ALKALI. 



RESULTS AT NEW MEXICO EXPERIMENT STATION. 



A detailed study of the water and alkali conditions 

 has been made by this station with the results herein- 

 after stated. The experiment was made on twenty acres 

 of land east of Roswell, N. M., the preparations for 

 the experiment having been completed by May 1st, 1900. 

 Now comes the sequel, as related in the Portales (N. M.) 

 Herald : 



In the summer and autumn of 1900 the alkali 

 flat was given a number of heavy irrigations. It was 

 intended to break up the land adjacent to the drains in 

 the spring of 1901 and plant it in narrow plats, running 

 north and south, to various crops, continue the flooding 

 and study the effects of the varying depths of water 

 table and the alkali on the growth of these crops. It 

 was also desired at the same time to study the necessary 

 depths, distances apart and cost of the drains, and 

 they were arranged with this end in view. The land 

 selected for this experiment is a part of the Hondo 

 bottom. It extends from the Hondo river southward 

 to the foot of the slope which forms the south boundary 

 of the river bottom. The surface of the land rises from 

 the bottoms rather abruptly at first for about 300 feet, 

 and then more gradually off toward the south and south- 

 west. 



The line for the central drain was selected at the 

 narrowest part of the bottom land, the width here be- 

 ing about one foot in the first 100 feet from the river 

 and of about half a foot in the remaining 500 feet. 

 There is also a slight fall toward the east. In addition 

 to the general slope to the south and east there are a 

 few well marked depressions in the surface. The Pierce, 

 Cunningham and Ballard irrigating canal is situated 

 about midway on the abrupt portion of the slope, at 

 this point about 150 feet from the end of the central 

 drain. The soil of this slope contains a large amount 

 of gypsum, is somewhat gravelly, and allows water to 

 pass through it quite readily, so that the seepage from 

 the canal is large. 



About a quarter of a mile to the south, and on 

 higher ground, there is another canal, running from 

 west to east, through the adjacent 40 acres. The soil 

 through which this canal runs is loam, underlaid by 

 gravelly material derived from limestone conglomerate, 

 which extends down to the bottom land. The nature 

 of the soil makes it probable that this canal also loses 

 considerable water which finds its way down to the flat. 



The greater portion of the flat was covered with 

 bunch grass, called salt grass, in which there were some 

 bare spots. The wettest portions were covered with 

 true salt grass, and where water stood on the surface, 

 in the depressions, with tule. The most important of 

 the plants going under the name of tule are there. 

 On the slope, from the ditch to the flat, the surface foot 

 is mainly a sandy loam, and the second foot is loam. 

 Below two feet the soil is lighter in texture and con- 

 tains a large proportion of gypsum with gravel. The 

 soil of the bottom land is the Hondo meadow type, con- 

 sisting principally of the sediment which has been de- 

 posited by floods. The texture of the first foot 



varies from a heavy clay loam on the south side to a 

 light loam on the north side, next the river. The second 

 and third feet vary from clay on the south to clay 

 loam on the north side. Although the most of this soil 

 is quite heavy in texture, rt appears much lighter when 

 examined in the field. Its true texture is brought out 

 on attempting to mix it with water, when it is found 

 to be quite difficult to make into mud, for it acts like 

 a very pure clay. When wet lumps of the deeper layers 

 of the pete and muck were thrown out, in ditching, and 

 allowed to dry, instead of baking very hard, as does the 

 heavy soils of the Rio Grande valley, they soon crumbled 

 into soil of splendid tilth. The breaking down reminds 

 one of the slacking of lime. A practical application of 

 these observations lies in the fact that if such a soil 

 is cultivated when in proper moisture condition it is 

 easily gotteu into good tilth, but when worked too 

 wet it will puddle and become very heavy and difficult 

 to handle. 



The drainage system consists of a main central 

 drain 610 feet long running from the foot of the slope 

 to the Hondo, its direction being about three degrees 

 west of north. This drain is laid on a grade of four 

 inches to the hundred feet. The first 100 feet from 

 the Hondo is open, the next 270 feet is laid with 8-inch 

 tile, and the upper 240 feet with 6-inch tile. At the 

 foot of the slope the central drain is extended 150 feet 

 southwest, somewhat parallel with the P. C. and B. 

 canal, and laid with 6-inch tile. 



On the east side of the center there are 12 lateral 

 drains making an angle of about 18 degrees with the 

 main drain, parallel to each other and 155 feet long. 

 The first eight, from the south, are 30 feet apart, and 

 laid with 3-inch tile at depths between 2 and 3~y 2 feet; 

 the next three are 40 feet apart, laid with 4-inch tile, 

 and their depths are from Zy 2 to 4% feet, and their 

 greatest depth being where they join the main and the 

 least at their east ends, due both to their grade and 

 the slope of the land toward the east. The twelfth drain 

 is 100 feet from the eleventh, is laid with 5-inch tile 

 and has a mean depth of about 4% i^et. 



On the west side of the main there are seven drains, 

 each 155 feet long, and these also make an angle of 

 about 18 degrees with the main. The first four are 

 laid with 3-inch tile at a depth of from 3 to 3y 2 feet, 

 and 60 feet apart, the next two are laid with 4-inch tile 

 at a depth of from 3~y 2 to 4 feet, and 60 feet apart. 

 The seventh is laid with 5-inch tile at a depth of about 

 4% feet, and is 100 feet from the sixth. The end of 

 the main drain, where it empties into the river, is about 

 63/2 feet deep. 



The slope of the land was such as allowed the east 

 end of some of the drains to come within two feet of 

 the surface, while the greatest average depth of any 

 of them was about 5 feet. This gave an opportunity 

 for studying the effect of various depths of water table 

 on the rate of removal of alkali, and on the growth 

 of crops. It was our intention to plant a portion of 

 area to various crops in narrow plats running north 

 to south^ but unfortunately this portion of the experi- 

 ment could not be carried on. The drains were put in 



