Soil Resources and Sustainable Agriculture
1. Which of the following is not a component of soil? (p. 228)
A. terrestrial animals
B. microorganisms
C. weathered minerals from rocks
D. partially decomposed organic matter
E. none of the above
2. Under the best of circumstances, soil can accumulate at the rate of (p. 228)
A. 1 meter/decade.
B. 1 meter/year.
C. 1 cm/year.
D. 1 mm/year.
E. none of the above.
3. Soil characteristics include all of the following EXCEPT (p. 229)
A. particle size.
B. amount of organic material.
C. clay or sand content.
D. number of plants.
E. none of the above.
4. Which soil microorganisms capture sunlight and manufacture new organic compounds? (p. 230)
A. bacteria
B. actinomycetes
C. algae and blue-green bacteria
D. roundworms
E. all of the above
5. Soil contains many horizontal layers called (p. 230)
A. topsoils.
B. parent materials.
C. subsoils.
D. soil horizons.
E. none of the above.
6. Which layer of soil has a lower organic content, higher concentration of minerals, and can sometimes be cemented into an impermeable layer called "hard pan"? (p. 230)
A. topsoil
B. subsoil
C. bedrock
D. surface litter
E. none of the above
7. Approximately what percentage of the earth's land surface area is currently under agricultural use? (p. 231)
A. 10%
B. 25%
C. 50%
D. 80%
E. 90%
8. Increased population means increased demand for food. Which geographic areas have seen an increase in land devoted to agricultural use over the last thirty years? (p. 231)
A. Oceania
B. South America
C. North America
D. Europe
E. A and B
F. C and D.
9. According to United Nations estimates, the percentage of world's soils that is moderately to extremely degraded is about (p. 233)
A. 10%.
B. 25%.
C. 60%.
D. 80%.
E. 100%.
10. Chemical deterioration of soils includes (p. 234)
A. salination.
B. nutrient depletion.
C. acidification.
D. pollution.
E. all of the above.
11. Degraded soil tends to (p. 234)
A. not hold water as well as non-degraded soil.
B. result in lower crop yields.
C. result in few livestock per acre.
D. diminish wildlife diversity.
E. all of the above.
12. Current soil erosion is the equivalent of reducing world crop land by (p. 235)
A. 1% every decade.
B. 10% every year.
C. 1% every year.
D. 50% every year.
E. none of the above.
13. All of the following are the result of soil erosion EXCEPT (p. 235)
A. sediment loading of rivers and streams.
B. reduction in crop production.
C. increase frequency of floods.
D. makes rivers unnavigable.
E. decreased use of fertilizers.
14. In the years from the early 1980s to the early 1990s, soil erosion in the United States (p. 236)
A. declined by 1/3.
B. increased by 1/3.
C. increased by 3 times.
D. decreased by 3 times.
E. none of the above.
15. If you were to think about the soil as a bank, where deposits were made for centuries to create the current soil, what are the total costs of soil erosion in the United States? (p. 236)
A. $500,000/year
B. $500 million/year
C. $500 trillion/year
D. $5,000/year
E. none of the above
16. A graphic example of the effects of soil loss is what erosion has done to the Huang (Yellow) River in China, which flows through the loess deposits on the North China Plateau. If you were to visit, you would find (pp. 236-237)
A. that the Yellow River carries more than four times the soil load of the Mississippi River.
B. that sediment settling has raised the river bottom by 30 feet.
C. that the Plateau is losing the equivalent of 1.2 inches of topsoil per year.
D. A and C.
E. all of the above.
17. When mineral deposits accumulate on the surface of the soil due to irrigation this is called (p. 238)
A. waterlogging.
B. high evaporative losses.
C. salinization.
D. water conservation.
E. all of the above.
18. Overfertilization can lead an increased concentration of this chemical in drinking water, a chemical to which young children are especially sensitive: (p. 238)
A. nitrates
B. phosphates
C. potassium
D. chlorophyll
E. none of the above
19. Green revolution agriculture has resulted in (pp. 238-240)
A. increased agricultural output.
B. huge increases in energy input.
C. loss of crop diversity.
D. increased nitrate levels in groundwater.
E. all of the above.
20. Sustainable agriculture relies on which of the following techniques to reduce chemical inputs and soil loss (p. 242-244)
A. contour plowing.
B. mulching.
C. synthetic fertilizers, rather than manure.
D. maximum till practices.
E. A and B.
F. C and D.