Irrigation Efficiencies MCQ with answer and solution

Concept

Sprinkler irrigation is best for uneven (undulating) land and light sandy soils with high infiltration, where surface irrigation fails.

Step-by-step solution

1. Surface (flood) irrigation needs level land and soil that does not soak water too fast. 2. On undulating land, surface flow is uneven. Levelling is costly. 3. In sandy soil, infiltration is high, so flood water is lost by deep percolation near the head. 4. A sprinkler sprays water like rain, so land levelling is not needed and water use is controlled. 5. So the sprinkler is best for undulating sandy soil. Answer (D).

Explanation

A sprinkler gives water like rainfall, so it works well on uneven land without levelling. Sandy soil takes water fast, so flood irrigation wastes water, but a sprinkler gives a controlled amount. So undulating sandy soil is the best case for sprinkler irrigation.

Why the other options are wrong

A: Heavy soil with low infiltration causes ponding and runoff under sprinklers. Surface methods suit it better. B: Alluvial soil on flat land is easily irrigated by surface methods. C: Level surface suits cheap flood, border or furrow irrigation, so a sprinkler is not needed.

Shortcut

Sprinkler = Sandy + Sloping/undulating land.

Common mistake

Choosing level surface because it seems easy. Level land actually favours surface irrigation.