Question

Read the following statements about border irrigation carefully:
A. Width of borders usually varies from 10 to 25 m.
B. For a sandy and sandy loam soil on moderate slopes and small to moderate irrigation streams, border length ranges from 30 to 90 m.
C. For a medium loam soil on moderate slopes and small to moderate irrigation streams, border length ranges from 100 to 180 m.
D. For a clay loam and clay soil on moderate slopes and small to moderate irrigation streams, border length ranges from 120 to 350 m.
Choose the correct answer from the options given below:

• A. A, B and D only
• B. C only
• C. A and D only
• D. B, C, and D

Hint:

In border irrigation design, the length of the border is directly proportional to the soil texture (heaviness): - Coarse soils (sand): Short borders. - Medium soils (loam): Medium borders. - Fine soils (clay): Long borders.

Answer 1

The Correct Option is C

Step 1: Assess each statement regarding border irrigation design parameters.
- Statement A: Border strip width is determined by land slope and farm machinery size, typically ranging from 10 to 25 m. This statement is generally accurate.
- Statement B: Sandy and sandy loam soils exhibit high infiltration rates, necessitating shorter border lengths to prevent premature water loss. A range of 30 to 90 m is excessively long for these soil types; shorter lengths are customary. This statement is likely inaccurate.
- Statement C: Medium loam soils have moderate infiltration rates, permitting longer border lengths than sandy soils. A range of 100 to 180 m is a suitable and common recommendation for these conditions. This statement is accurate.
- Statement D: Clay loam and clay soils possess low infiltration rates, allowing for very long border lengths due to slow water penetration. A range of 120 to 350 m is appropriate for these heavy soils. This statement is accurate.
Step 2: Determine the correct combination.
Statements A, C, and D reflect correct design principles for border irrigation. Statement B proposes lengths that are too long for coarse-textured soils.
Consequently, A, C, and D constitute the optimal combination.