4.2 Soil Formation And Erosion

Which horizon in a soil profile contains the most organic matter?

A. O horizon

What is the process by which rocks and minerals are broken down by natural forces like water, wind, and temperature changes called?

C. Weathering

What is the primary cause of soil erosion on a deforested slope?

B. The absence of plant roots to hold soil in place

Which soil texture has the highest water-holding capacity?

C. Clay soil

In a typical soil profile, which layer would you expect to have the least organic material?

D. C horizon

Which soil conservation technique involves planting along the natural contours of the land?

B. Contour plowing

Which soil component is most susceptible to erosion by wind and water?

A. Sand

Which statement about soil degradation is correct?

C. It can result from both deforestation and overgrazing.

What property is determined by the relative amounts of sand, silt, and clay?

B. Texture

What term describes the process in which soil nutrients are washed away from the soil by water?

B. Leaching

A soil profile that is rich in iron and aluminum oxides and low in organic material is likely found in which horizon?

C. B horizon

Which practice can help increase the porosity of soil, thereby improving drainage?

C. Increasing organic content

What type of weathering occurs when rock is broken down by plant roots or burrowing animals?

B. Biological weathering

Soil that is 40% sand, 40% silt, and 20% clay is classified as what?

B. Loam

Which soil horizon is known as the 'zone of accumulation' where minerals like iron and clay accumulate from above?

B. B horizon