FACTORS OF AGRICULTURAL PRODUCTION 151 



lower lands. But lands which are low or flat or badly drained 

 are frequently so strongly impregnated with these salts as to 

 interfere with plant growth or to destroy it altogether. 



In the arid regions of every part of the globe these alkali 

 lands are of frequent occurrence, forming a part of the landscape, 

 which is repellent because of its dreary barrenness and disa- 

 greeable because of the fine powdery dust which is blown about 

 by the winds, parching to the lips and stinging to the eyes and 

 nostrils of the traveler. It is impossible to make any estimate 

 of the amount of land which goes to waste on this account, 

 partly because it is not known just how much there is of it, and 

 partly because much of it would be unusable anyway on account 

 of insufficient moisture. But inasmuch as it is usually the lower 

 and less arid land of an arid region which is alkaline, it fre- 

 quently happens that such lands are highly productive if these 

 bad chemical conditions can be overcome. Therefore it is a 

 problem of importance, and nowhere is it greater than in the 

 western part of the United States. 



Without attempting a detailed discussion of the methods of 

 reclamation, the following are named as having been found 

 effective, 1 though they require technical knowledge and skill to 

 make them successful : 



[. Underdrainage. By this means the water is allowed to 

 leach the salts out of the soil and carry them away. This is said 

 by Hilgard to be the final and universal remedy. 



n. Leaching down. That is, without underdrainage, the alkali 

 on the surface can sometimes be carried down several feet by 

 flooding the land. 



3 . Removing a few inches of the surface soil bodily from the 

 land. Since the salts are carried to the surface in solution with 

 the water and there left when the water evaporates, it generally 

 happens that the surface is more strongly impregnated than the 



1 Cf. E. W. Hilgard, Soils (New York, 1906), chaps, xxii, xxiii. 



