THE TREATMENT OF ALKALI. 43 



from them. In some portions of the San Luis valley, 

 in Southern Colorado and elsewhere in the west, this 

 trouble has become most serious, fertile lands long 

 under successful cultivation being rendered useless by- 

 thousands of acres, unless an expensive system of 

 under drain age is undertaken. One plan which can be' 

 operated early in the spring, before the regular irri- 

 gating season, has been tried quite successfully and is 

 described in a few words : An eighty -acre tradl is 

 divided into plots or rooms 8 x 32 rods by means of 

 dikes, such as described in the Mexican border system 

 of applying water. This should be done in the fall so 

 that they will be solid in the vSpring. The formation 

 in the San Luis valley is first a surface soil of two feet 

 over two feet of clay and gravel, then eight inches 

 of quicksand overlying the hard-pan, which is from 

 eight to eighteen inches thick. Below this is forty 

 feet of dry sand. 



As soon as the frost is out, and while water is 

 plenty, turn a large head into an upper corner border 

 at the supply ditch. When it is filled, open a passage 

 into the next border, and so on until it reaches the 

 waste ditch at the lower end of the field. In the waste 

 ditch drill an inch hole down to the hard-pan and put 

 in a stick of giant powder which will blow out a hole 

 as large as a barrel. A more simple and safer method 

 in making these escapements would be to use a post- 

 auger. When the water, black with alkali, reaches 

 the waste ditch it immediately runs through these 

 holes and is lost underneath in the sand. Keep the 

 water running as long as it is discolored. Some of 

 the worst land in the valley has been reclaimed in this 



