Question

What happens when rain falls on soil without vegetational cover?

• A. Rainwater percolates in soil efficiently
• B. Rainwater causes loss of surface soil
• C. Rainwater leads to the fertility of the soil
• D. Rainwater does not cause any change in soil

Answer 1

The correct option is B

Rainwater causes loss of surface soil

The correct option is B.

The explanation for the correct option:

1. Soil is the uppermost weathered layer of the earth's crust.
2. It is composed of organic matter, mineral particles, water, and air.
3. The denudation of the upper layer of soil is referred to as soil erosion.
4. Human activities like over-cultivation, unrestricted grazing, deforestation, and poor irrigation practices can cause soil erosion.
5. Vegetation cover plays a very important role in protecting the soil surface from raindrop splashing.
6. It prevents soil erosion by rainwater.
7. Trees are natural absorbers because their roots absorb water and tightly hold the soil in place after heavy rainfall.
8. It decreases the amount of sediment that enters rivers while enhancing water absorption into the earth.

The explanation for incorrect options:

Option A -

1. The presence of rainfall influences water infiltration; the more the vegetation, the less water will runoff.
2. In the absence of vegetation cover, the rainwater is not absorbed efficiently.

Option C-

1. On soils without vegetation cover, the nutrients in the soil can run off with rainwater.
2. Rainwater decreases the fertility of the soil.

Option D -

Rainwater causes erosion of soil without vegetation cover.

Final answer: When rain falls on soil without vegetational cover, rainwater causes loss of surface soil.