44 IRRIGATION FARMING. 



way. After flooding, good judgment must be used in 

 working the ground before it bakes. Two floodings 

 will cure the most obstinate case and a fortnight is 

 usually required to thoroughly flood eighty acres. 



Chemical Antidotes. — When the quantity of 

 alkali is small the evil effedls resulting from its pres- 

 ence may be mitigated by the application to the soil of 

 chemical antidotes. A cheap antidote for most alka- 

 line salts is lime. In some cases neutral calcareous 

 marl will answer the purpose. When the alkali con- 

 sists of carbonates and borates, the best antidote is 

 gypsum or land plaster. These materials should be 

 sown broadcast over the surface and harrowed in to a 

 moderate depth prior to irrigating. The usual amount 

 of gypsum to apply is from 400 to 500 pounds to the 

 acre. A California professor once became so inocu- 

 lated with the gypsum dodlrine that he applied 3,600 

 pounds to the acre and was satisfied that the process 

 proved to be altogether too expensive, although it re- 

 moved 75 per cent, of the alkali by using the gypsum 

 in connedlion with the flooding method. Gypsum is 

 the only cure for the disastrous black alkali so fatal to 

 plant life. 



Eradication by Vegetable Growth. — It may 

 often happen that all of the foregoing recommendations 

 will prove ineffe(5live, and to many cultivators they 

 may be inaccessible. The most simple and natural 

 remedy to absorb the alkaliferous elements in the soil, 

 as has been found from the writer's own experience, 

 is by growing them out with certain neutralizing crops. 

 If these do not entirely eradicate alkali in one season 

 they should be continued year after year until the 



