Step 1: Understanding Assertion (A).
Irrigation is indeed practiced widely in India due to the variability in rainfall and climate across the country.
Step 2: Understanding Reason (R).
India's variety of soil types, such as alluvial, black, and red soil, affects agricultural practices, but it is not directly related to the need for irrigation. The primary reason for irrigation is the irregular distribution of rainfall.
Step 3: Conclusion.
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation for Assertion (A), as irrigation is needed due to the irregularity of rainfall rather than the variety of soil types.
Final Answer: Both (A) and (R) are true but (R) is not the correct explanation of (A).