THE ALKALINE SOILS 



35 



Alkali Lands 



In countries of heavy rainfall, the alkaline materials are leached out 

 in the drainage waters. In arid countries there is very little or no 

 leachage ; the water passes off by evaporation, and the alkaline and 

 other materials in solution are left at or near the surface of the ground. 



The normal condition of arid lands is illustrated in the table below 

 (Means). The first part gives the percentage of total soluble salts 

 in two soils from central Montana, where neither soil originally con- 

 tained enough alkali within the zone of root action to be detrimental. 

 The second part shows the condition of these soils after a few years 

 of judicious irrigation, and the third part displays the condition after 

 a few years of irrigation without drainage : — 



Table showing percentage of alkali in soils 



