THE IRRIGATION AGE. 



169 



dry old toper. They will not help out 

 much of a crop on a dry subsoil. 



Ou the desert many a crop suffers in this 

 way. At the first irrigation, after being 

 dry for ages, it is wet down say four feet. 

 The irrigator thinks this enough. It may 

 be if the sheet water below is near enough 

 to furnish moisture by capillary attraction. 

 But in some soils moisture does not rise 

 in that way one-quarter of the height it is 

 geuerally supposed to, and in very fine 

 soils does not rise one-half. Sheet water 

 is a fine reliance for many things, if you 

 are sure you have it and sure how high the 

 moisture rises. But until you are positive 

 on this point you had better put into the 

 subsoil all the winter and spring water you 

 can, unless you are certain it will damage 

 the crops. And in irrigating desert for the 

 first time, if it is many feet to water below, 

 you can hardly get too much in. If you 

 should put in two acre feet per month for 

 the whole first winter you might have the 

 top a little too wet for the first crop, but 



the succeeding crop would be. better than 

 if you had to fight a dry subsoil. When 

 the subsoil is once thoroughly soaked it is 

 quite an easy matter to keep it so. But a 

 dry one is the last thing you want to fight. 

 You can beat the dry est air and hottest sun 

 with water on the surface and good culti- 

 vation of the top soil, but if the subsoil is 

 sapping the moisture all the time you have 

 a hidden enemy that is worse than the 

 open ones. 



When you have investigated this subject 

 thoroughly you will reach the conclusion 

 that for all around good results a subsoil 

 that will hold moisture not water but 

 moisture is very essential to the best cul- 

 tivation of the soil for field, garden or or- 

 chard, and that its condition needs watch- 

 ing almost as much as that of the top soil. 

 And nothing will so enable you to get 

 along with little water at the time of year 

 when it is scarce like keeping this well 

 filled at the time of year when water is 

 plenty and no one wants it. 



THE L\I;<;K CANAL. PECOS VALLEY SYSTEM IN NK\V MEXICO. 



