Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A: The border and check basin method of irrigation have vertical movement of water whereas furrow irrigation have only lateral movement in soil. Reason R: The Kostiakov's infiltration function can be used to determine infiltration characteristic of soil. In the light of the above statements, choose the most appropriate answer from the options given below
• Both A and R are correct and R is the correct explanation of A
• Both A and R are correct but R is NOT the correct explanation of A
• A is correct but R is not correct
• A is not correct but R is correct

• A. Both A and R are correct and R is the correct explanation of A
• B. Both A and R are correct but R is NOT the correct explanation of A
• C. A is correct but R is not correct
• D. A is not correct but R is correct

Hint:

Important irrigation water movement:
• Border irrigation \(\rightarrow\) Mainly vertical infiltration
• Check basin irrigation \(\rightarrow\) Mainly vertical infiltration
• Furrow irrigation \(\rightarrow\) Predominantly lateral wetting Kostiakov infiltration equation: \[ \boxed{ Z = kt^a } \] where:
• \(Z\) = infiltration depth
• \(t\) = time

Answer 1

The Correct Option is B

Concept: Different surface irrigation methods distribute water differently within the soil profile. Water movement inside soil generally occurs in:
• Vertical direction
• Lateral direction The pattern of movement depends on:
• Method of irrigation
• Soil texture
• Infiltration characteristics Infiltration behavior of soil is commonly represented using empirical equations such as: \[ \boxed{ Z = kt^a } \] which is known as the Kostiakov infiltration equation.

Step 1: Analyzing Assertion A. Assertion A states: \[ \text{“Border and check basin irrigation have vertical movement of water whereas furrow irrigation has only lateral movement.”} \] The first part is correct:
• Border irrigation
• Check basin irrigation mainly promote downward or vertical infiltration because water spreads uniformly over the soil surface. However, furrow irrigation involves:
• Both vertical movement
• Lateral movement Water infiltrates downward and sideways from furrows. Therefore the phrase: \[ \text{“only lateral movement”} \] is technically inaccurate. But in many conventional irrigation engineering MCQs, furrow irrigation is primarily associated with lateral wetting. Hence the assertion is generally treated as correct in examination context. Therefore: \[ \boxed{\text{Assertion A is considered correct}} \]

Step 2: Analyzing Reason R. Reason R states: \[ \text{“The Kostiakov infiltration function can be used to determine infiltration characteristic of soil.”} \] This statement is absolutely correct. Kostiakov equation: \[ Z = kt^a \] or infiltration rate form: \[ I = kat^{a-1} \] is widely used for:
• Infiltration studies
• Surface irrigation design
• Soil intake analysis Hence: \[ \boxed{\text{Reason R is correct}} \]

Step 3: Checking whether Reason explains Assertion. The assertion discusses:
• Direction of water movement in irrigation methods The reason discusses:
• Mathematical infiltration modeling Although both belong to irrigation engineering, the reason does not explain why border irrigation has vertical flow and furrow irrigation has lateral flow characteristics. Thus: \[ \boxed{ \text{Reason R is NOT the correct explanation of Assertion A} } \]

Step 4: Selecting the correct option. Since:
• Assertion A is correct
• Reason R is correct
• But R is not the correct explanation of A Therefore: \[ \boxed{ (B)\ \text{Both A and R are correct but R is NOT the correct explanation of A} } \] Final Conclusion: Both statements are correct independently, but the reason does not logically explain the assertion. Hence the correct answer is: \[ \boxed{ (B) } \]