When rain falls on soil without vegetational cover, it causes loss of surface soil.
Explanation:
Without vegetation to hold the soil in place, rainwater can easily wash away the topsoil, leading to erosion. The flowing water can also carry away soil particles, exacerbating the erosion process.
Why other options are incorrect:
(a) Rain water percolates in soil efficiently:
While some rainwater may percolate into the soil even without vegetation, the lack of plant roots and organic matter significantly reduces the soil’s ability to absorb and retain water. The majority of the water will run off the surface.
(c) Rain water leads to fertility of the soil:
Rainwater can contribute to soil fertility when it percolates through the soil and carries nutrients. However, without vegetation to absorb and utilize these nutrients, the rain’s positive impact on fertility is minimal. In fact, the erosion caused by rain on bare soil can lead to the loss of valuable nutrients.
(d) Rain water does not cause any change in soil:
Rainwater inevitably interacts with soil, even in the absence of vegetation. It can cause erosion, alter soil moisture levels, and impact the soil’s microbial activity.