282 Irrigation and Drainage 



DISTRIBUTION OF ALKALIES IN THE SOIL 



The position in the soil where the alkalies may be 

 found in greatest abundance varies under different con- 



Fig. 51. Growth of maize on black marsh soil in Wisconsin. 



ditions. Where there is a large and prolonged evapo- 

 ration at the surface, the alkalies may be nearly all 

 collected within the surface 3 or 4 inches, and hence be- 

 come so strong as to do serious injury, when if this 



