Which one of the following conditions is favorable for sprinkler irrigation method?
- AWhen the land topography is regular
- BWhen the soil is not easily erodible
- CWhen the water table is low
- DWhen the land soil is excessively permeableCorrect
Solution
Concept
Sprinkler irrigation suits soils that are too permeable, erodible or uneven for surface irrigation.
Step-by-step solution
1. Sprinkler irrigation sprays water like rain over the crop. 2. It is preferred where surface irrigation fails or wastes water. 3. Highly permeable (sandy) soil loses too much water by deep percolation in flooding, so sprinkler is better. 4. It also suits irregular topography and easily erodible soil. 5. Regular land, non-erodible soil and low water table do not specially need sprinklers. 6. Answer is (D).
Explanation
In very permeable soil, flood water goes down quickly and much water is lost. A sprinkler gives water slowly like rain, so the loss is small and distribution is uniform. That is why excessively permeable soil favours the sprinkler method.
Why the other options are wrong
(A) Regular topography suits surface methods; sprinklers are favoured on irregular land. (B) Sprinklers are favoured when soil is easily erodible, not when it is non-erodible. (C) A low water table is not a special condition that favours the sprinkler method.
Shortcut
Sprinkler is used where flooding is bad: sandy (very permeable) soil, uneven land, erodible soil.
Common mistake
Choosing 'regular topography' as the answer. Sprinklers are actually most useful on irregular land.
Correct answer: D) When the land soil is excessively permeable