ALKALI SALTS 403 



they tend to produce combine to injure the crop. The 

 methods already mentioned for treating alkali land are 

 of service on these small areas, and, in addition, the 

 plowing-under of fresh farm manure has been found to 

 improve their productiveness. This, with surface drain- 

 age, deep tillage, and good cultivation in order to prevent 

 the soil from drying out, will usually remedy the difficulty. 

 In many cases these spots become highly productive under 

 proper treatment. 



