Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
In light of the above statements, choose the correct answer from the options given below.
- Assertion (A) is True: The application of gypsum ($ ext{CaSO}_4\cdot 2 ext{H}_2 ext{O}$) is the standard chemical reclamation practice for sodic (alkali) soils.
- Reason (R) is True: Soluble $ ext{Ca}^{2+}$ provided by gypsum replaces exchangeable $ ext{Na}^+$ on soil clay colloids via cation exchange ($ ext{Soil-Na}_2 + ext{CaSO}_4 \rightarrow ext{Soil-Ca} + ext{Na}_2 ext{SO}_4$), allowing sodium to be leached out as soluble sodium sulfate.
- Relationship: Because $ ext{Ca}^{2+}$ replaces exchangeable sodium to flocculate colloids and eliminate sodicity, Reason (R) directly explains Assertion (A).
- Conclusion: Both (A) and (R) are correct and (R) is the correct explanation of (A) (Option 1).
Correct option: (1) Both (A) and (R) are true and (R) is the correct explanation of (A)