Heyy guys I need some help in the acids bases chapter.
Describe and explain the importance of controlling acidity in soil.
Is it just that different plants require different acidity for growth. Can anyone please explain a little more?
Soil may become acidic after a number of years. This can be due to acid rain, bacteria and fungi rotting the vegetation so that it releases acids or use of fertilisers containing ammonium salts.
Many crop plants such as onions, cabbage and beans grow better if the soil is neutral. If soil acidity drow below pH 5.5 many plants will not grow well.
We can remove excess acidity from the soil by adding crushed limestone - calcium carbonate. This neutralises the acid. The calcium carbonate and the products are neutral.
CaCO
3 + 2H
+ -> Ca
2+ + CO
2 + H
2O
Farmers often add lime (calcium oxide) to the soil. This also neutralises excess acid.
CaO + 2H
+ -> Ca
2+ + H
2O
However, care must be taken to ensure not too much lime is added to the soil. This is because lime is strongly alkaline when it dissolves in water. Most plants do not survive alkaline conditions. Therefore, if the soil does become too alkaline, farmers spray the soil with manure or even with very dilute sulphuric acid.
I hope this has cleared your doubt.