ALKALI LANDS AND THEIR RECLAMATION 



291 



Small spots a few rods in diameter occur in southern Illinois in 

 which the soluble salts form a deposit that looks like a heavy 

 white frost or light snow. Analysis shows this to be sodium sulfate. 

 It has been brought to the surface by seepage from higher land. 



In the glaciated area of the Middle West alkali soils occur in 

 many low, swampy places, usually in small patches of a few square 

 rods, but in some cases extend over many acres. During dry spells 

 whitish incrustations appear on the surface of the soil that disap- 

 pear with rains (Fig. 133). These alkali areas almost always con- 



Fio. 133. A dwarfed bushy or loafy porn plant (jrowinjf on nlkali soil of humid nron. 

 Sholls arc nearly always indications of alkali. 



tain large quantities of magnesium carbonate, and when this com- 

 pound amounts to more than one per cent crops such as corn and 

 oats are badly affected. The corn does not grow well, and where 

 strongly impregnated with the carbonate is bushy and the blades 

 turn brown or reddish. If a smaller amount is present the blades 

 are striped with yellow. Very little grain is produced. Oats 

 make a rank growth, but almost invariably lodge. 



Drainage is the ultimate remedy, but the process is slow when 

 only the natural rainfall is depended upon. 



