Soil Erosion and Conservation Quiz

Which of these does not cause weathering of rocks?

• rain

• pollution

• wind

• force of flowing water

Answer explanation

Weathering refers to the breakdown of rocks at or near the Earth's surface. It is caused by various physical and chemical processes. Rain, wind, and flowing water are all agents that can contribute to weathering. Pollution, while harmful to the environment in many ways, is not a direct physical force that causes rocks to break down. 

Which of these ways of soil erosion is not caused by humans?

• deforestation

• fast flowing river

• overgrazing

• ploughing

Answer explanation

While humans can contribute to increased river flow through activities like deforestation, the natural flow of a river itself is a geological phenomenon independent of human actions. Deforestation, overgrazing, and ploughing are all human activities that significantly increase soil erosion by removing vegetation cover that protects the soil from wind and water. 

Which of these can be caused by soil erosion?

• drought

• cyclone

• flood

• earthquake

Answer explanation

When soil is eroded, the protective layer of vegetation and topsoil is removed, exposing the underlying soil to the elements. This lack of vegetation cover makes the soil more susceptible to wind and water erosion, further exacerbating the drought conditions. Drought is a period of prolonged dryness, and with less vegetation to hold the soil in place, the erosion process intensifies, leading to a decrease in water retention capacity and even desertification in extreme cases. 

Which of these measures is most useful in preventing soil erosion by water in hilly areas?

• covering the soil

• building embankments

• step farming

• growing hedges along farmlands

Answer explanation

Terrace farming, or step farming, creates flat platforms on slopes, which slows down water flow, allowing it to infiltrate the soil rather than washing it away. This significantly reduces erosion and also increases the amount of cultivatable land on hillsides. 

Soil takes more time to form than to get eroded.

• True
• False

Answer explanation

Yes, the statement is accurate. Soil formation is a very slow process, taking hundreds or even thousands of years to create a thin layer of topsoil. In contrast, soil erosion, the removal of topsoil by natural forces or human activities, can occur relatively quickly, even within a single year. 

Roots of plants bind the soil particles and prevent soil erosion.

• True
• False

Answer explanation

Yes, it's true that plant roots play a crucial role in preventing soil erosion. They act as natural anchors, binding soil particles together and reducing the likelihood of them being washed away by wind or water. This binding effect is due to the physical presence of roots interwoven within the soil and also due to biological processes where roots release compounds that help cement soil particles together. 

Soil erosion due to flowing water is more on hill slopes than on plains.

• True
• False

Answer explanation

Yes, it's true that soil erosion due to flowing water is generally more pronounced on hill slopes than on plains. This is primarily because steeper slopes cause water to flow faster, increasing its erosive power and ability to carry away soil particles. 

Soil in farmlands is less likely to get eroded after a crop is harvested

• True
• False

Answer explanation

No, it is incorrect to state that soil in farmlands is less likely to get eroded after a crop is harvested. In fact, the opposite is generally true. After a crop is harvested, the soil is often left bare and exposed, making it more susceptible to erosion from wind and water. 

Terrace farming is done mainly to reduce soil erosion due to wind.​

• True
• False

Answer explanation

The statement is false. Terrace farming is primarily used to reduce soil erosion caused by water, not wind. While it can have some indirect effects on wind erosion, its main purpose is to create flat platforms on sloped land to slow down water runoff and prevent it from carrying away topsoil.