424 



SOILS. 



northward beyond the line of the United States ; southward, it 

 reaches far into Mexico, including especially the Mexican 

 plateau. In South America it includes most of the Pacific 

 Slope (Peru and Chile) south to Araucania; and eastward of 

 the Andes, the greater portion of the plains of western Brazil 

 and Argentina. In Europe only a small portion of the 

 Mediterranean border is included; but the entire African coast- 

 belt opposite, with the Saharan and Libyan deserts, Egypt and 

 Arabia, are included therein, as well as, south of the Equator, a 

 considerable portion of South Africa (Kalahari desert). In 

 Asia, Asia Minor, Syria (with Palestine), Mesopotamia, 

 Persia, and northwestern India up to the Ganges, and north- 

 ward, the great plains or steppes of central Asia eastward to 

 Mongolia and western China, fall into the same category; as 

 does also a large portion of the Australian continent. 



Utilisation of World-wide Importance. Over these vast 

 areas alkali lands occur to a greater or less extent, the excep- 

 tions being the mountain regions and adjacent lands on the side 

 exposed to the prevailing winds. It will therefore be seen 

 that the problem of the utilization of alkali lands for agricul- 

 ture is not of local interest only, but is of world-wide import- 

 ance. It will also be noted that many of the countries referred 

 to are those in which the most ancient civilizations have ex- 

 isted in the past, but which at present, with few exceptions, are 

 occupied by semicivilizecl people only. It is doubtless from 

 this cause that the nature of alkali lands has until lately been 

 so little understood, that even their essential distinctness from 

 the sea-border lands has been but recently recognized in full. 

 Moreover, the great intrinsic fertility of these lands when 

 freed from the noxious salts, has been very little appreciated ; 

 their repellent aspect causing them to be generally considered 

 as permanently waste lands. 



Repellent aspect. This aspect is essentially due to their natural 

 vegetation being in most cases confined to plants useless to man, com- 

 monly designated as "saline vegetation," J of which but little is usually 

 relished by cattle. Notable exceptions to this rule occur in North and 

 South America, Australia, and Africa, where the " saltbushes " of the 

 former and the " karroo " vegetation of the latter form valuable pasture 



1 See Chapter 23. 



