Answer to Question #86417 in Chemistry for Yashika

Question

How do soils become alkaline?Give the advantages and disadvantages of alkaline soils.

Answer 1

There are several causes that result in soil alkalinity. They comprise the accumulation of minerals forming sodium carbonate and sodium bicarbonate due to weathering processes and accumulation of sodium salts (sodium carbonate, bicarbonate, sulfate, hydroxide, hypochlorite, etc.) that are used in the industrial and domestic applications. In addition, coal-fired power plants produce ash containing calcium oxide that is dissolved in water producing slaked lime Ca(OH)2. The following precipitation of Ca ions leads to the accumulation of sodium carbonate that increases water and soil alkalinity. Finally, the soil becomes alkaline due to over-lining of acidic soils.

Alkaline soils are usually highly porous, freely draining and saturated with calcium carbonate whereas some plants grow better in alkaline soils. However, highly alkalinity impairs absorption of minerals by plants roots affecting their growth whereas some plants do not grow in alkaline soils.