270 MISCELLANEOUS FARM SUBJECTS 



economical irrigation is usually learned only when scarcity of water 

 compels its less lavish use. In any event some waste of water will 

 occur under the best of management, making draining in many 

 places essential to profitable farming. (Mont. Agr. Col. B. 76; 

 Wyo. Ex. Sta. 61; Kept. Office Ex. Sta. 1910.) 



Alkali. On irrigated lands one of the objects of drainage is to 

 rid the soil of an accumulating alkali which, if not removed even- 

 tually ruins the soil for productive purposes. A failure of his crops 

 is frequently the first intimation to the farmer that his soil is too 

 wet and that alkali in harmful quantities is present. Effective 

 drainage removes the cause of the accumulation, yet special treat- 

 ment is frequently required to remove the excess of alkali sufficiently 

 for growing crops. Copious irrigation, followed by thorough and 

 deep cultivation and the growing of alkali-resistant crops for a sea- 

 son or two, quite commonly restores the land to ite former productive 

 condition. Some fields, however, are so fully charged with salts, 

 due to seepage and to neglect in the use of preventive measures, that 

 a longer treatment by various methods of flooding, in connection 

 with the relief that is furnished by drainage, is required. Complete 

 drainage, however, is the first essential in such reclamation, but 

 should be followed by liberal irrigation until the alkali has been re- 

 moved sufficiently to permit the soil to grow a crop, after which the 

 quantity of water may be adjusted to the actual needs of the crops 

 which are to be grown. No fact has been more thoroughly developed 

 or forcibly emphasized by drainage experiments and ordinary field 

 practice than the value of timely attention to this subject as a pre- 

 ventive of seeped and boggy fields. The harmful deposition of al- 

 kali is generally from one of three causes : 



1st. Light rainfall, insufficient to wash out and transport the 

 harmful salts by surface run-off; which condition is strikingly prev- 

 alent in the Rocky Mountains West. 2nd. Poor drainage, prin- 

 cipally a lack of underground channels whereby water containing 

 the alkalis in solution is allowed to stagnate and perforce eventually 

 approach the surface. 3d. Excessive surface evaporation, inducing a 

 concentration and lodgment of salts at the root crowns of plants. 

 The source of alkali may be found primarily in the particular soils 

 themselves, or carried from soils so affected by the irrigation water 

 used. 



The ground waters passing through the lower formations take 

 up these salts and hold them in solution. When the ground water 

 reaches a point near the surface evaporation takes place removing 

 the water and leaving the alkali deposits upon the surface. The 

 productive power of the soil is thus lessened by excessive moisture, 

 and the consequent shutting out of air, and this impregnation of 

 alkali salts. The plans of treating land for the purpose of redeem- 

 ing it from alkali which has accumulated through evaporation and 

 seepage are not uniform, nor is there any practice which has been 

 so reduced to a system as to justify an authoritative statement of 

 methods that may be best employed. The cutting off of the under- 

 ground supply by drainage has often resulted in the full reclamation 



