A) increases crop yield
B) makes soil infertile
C) reduces water–logging
D) none of the above

Ans : (b) makes soil infertile

If excessive quantity of salts such as calcium, magnesium and potassium salts are present in soil, it may prove to be injurious and makes soil infertile. Sodium carbonate which is also called white alkali is very harmful for crops. When present less the 0.15% in soil they do not effect but if they are present more than 0.25% then the land becomes infertile.