21. Which of the following soil horizons is the layer of unconsolidated material that underlies the soil?
a. A horizon
b. B horizon
c. C horizon
d. R horizon
22. What is the term used to describe the process of soil particles being carried away by water?
a. Erosion
b. Leaching
c. Weathering
d. Deposition
23. Which of the following is a measure of the amount of organic matter in the soil?
a. pH
b. Cation exchange capacity
c. Bulk density
d. Soil organic matter
24. Which of the following nutrients is most likely to be deficient in a soil with a low pH?
a. Nitrogen
b. Phosphorus
c. Potassium
d. Calcium
25. What is the term used to describe the layer of soil that has been disturbed by human activities?
a. Plow layer
b. Compacted layer
c. Disturbed layer
d. Eroded layer
