Hydrologic Cycle
Which of the following is not true with respect to the hydrologic cycle?
A. More than 85% of the water evaporated from the earth's surface comes from oceans.
B. There is a net migration of some 40,000 km³ of water in clouds from the land area to the ocean areas.
C. The average residence time of water in clouds is about 10 days.
D. Some 78% of the total precipitation falls onto the oceans.
E. About one third of the readily accessible water in the hydrologic cycle is in the soil.
There is a net migration of some 40,000 km³ of water in clouds from the land area to the ocean areas.
Which of the following will increase the evaporation (E) from the soil surface?
A. Adding straw mulch to the soil surface
B. The use of no-till culture
C. Stubble mulch farming
D. Plastic mulch
E. None of the above
None
Land drainage is beneficial because _.
A. It increases the alternate of expansion and contraction due to freezing and thawing of soils
B. It increases the water-to-air ratio in the soil pores
C. It slows down the rate of soil warming in the spring
D. It increases the depth of root penetration in the soil
E. It increases the availability of iron and manganese in acid soils
It increases the depth of root penetration in the soil
Of the various types of drain systems, open ditch systems are most practical and economical for use on __.
A. Vertisols
B. Soils which do not freeze during the winter
C. Soils with a deep water table
D. Poorly drained soils with sandy profiles
E. Clay soils with poor drainage
Poorly drained soils with sandy profiles
Which of the following is not a characteristic of soil colloids?
A. Very small size
B. High external surfaces
C. Electronegative charges
D. Ability to exchange ions with the soil solution
E. Low water holding capacity
Low water holding capacity
Which of the following sources of water have the shortest average residence time?
A. Soil moisture
B. Clouds
C. Oceans and ice caps
D. Groundwater
Clouds
Which of the following locations in the United States would have the highest evaporation (E) from the soil surface in July?
A. A bare, unirrigated dry land soil in Colorado
B. An unirrigated soil in South Carolina growing cotton
C. A furrow-irrigated cotton field in Arizona
D. A forest woodland in Illinois
E. A corn field in New York
A furrow-irrigated cotton field in Arizona
Which of the following will not increase the efficiency of water use by plants in an irrigation system?
A. The use of concrete-lined delivery ditches
B. The use of flood irrigation for forage crops
C. The use of drip irrigation for fruit trees
D. The use of crop residues to reduce evaporation
E. The use of herbicides to control weeds
The use of flood irrigation for forage crops
If you dug a deep hole in your back yard and water started to seep into the hole it would fill the hole up to __.
A. The infiltration rate
B. The percolation rate
C. Field capacity
D. The water table
E. The liquid limit
The water table
Which of the following does not describe aluminum hydroxy ions (such as Al(OH)₂⁺) in the soil?
A. They are more prominent in acid than in neutral soils.
B. They affect the pH of the soil solution through hydrolysis.
C. They block negative sites on some clays thereby reducing the cation exchange capacity.
D. They influence the swelling of some clays by entering into the interlayer spaces.
E. They are commonly applied to help reduce the soil pH for acid-loving plants.
They are commonly applied to help reduce the soil pH for acid-loving plants
The expression, P - ET - SS estimates the __ a watershed.
Discharge volume from
Urban development of land under natural vegetation or agriculture usually greatly _ soil infiltration capacity and therefore greatly increases ___.
A. Decreases …… stream bank erosion.
B. Increases …… stream bank erosion.
C. Decreases …… groundwater recharge.
D. Increases ……. groundwater recharge.
Decrease... Stream bank erosion
Which of the following actions would best assure good aeration in a soil?
A. Increase the soil temperature
B. Add organic residues
C. Use a plastic mulch
D. Use cover crops, especially legumes
E. Remove excess water
Remove excess water
The most common form of on-site waste water treatment for homes not hooked up to sewer lines is the _.
A. Active composting method
B. Septic tank and drain field
C. Chemical “flush” system
D. Electrical induction sterilization
E. Soil enrichment process
Septic tank and drain field
Among the soils of which order would you most likely find the highest buffering capacities?
A. Alfisols
B. Vertisols
C. Oxisols
D. Spodosols
E. Ultisols
Vertisols
Which of the following would you expect to have the highest leaf area index?
A. Bare fallowed area
B. Corn three weeks after planting
C. Corn, knee high
D. Alfalfa just before harvest
E. Either B or C (equal)
Alfalfa just before harvest
Which of the following irrigation systems produces the most biomass per unit of water applied?
A. Flood irrigation
B. Furrow irrigation
C. Drip irrigation
D. Sprinkle irrigation
E. Furrow-dike irrigation
Drip irrigation
Which of the following is (are) considered necessary features for an area to be delineated as a wetland?
A. Hydric soils
B. Shallow standing water
C. Aquatic vegetation
D. Organic soils
E. All of the above
Hydric soils
Where high-value crops or individual ornamental shrubs are to be grown and water is expensive, the most efficient type of irrigation to use would be __.
A. Center pivot
B. Basin flooding
C. Furrow
D. Drip or trickle
Drip or trickle
Poor plant growth in a well-drained irrigated soil in an arid region (pH=8.0) is most likely due to __.
A. Manganese toxicity
B. Iron deficiency
C. Phosphate toxicity
D. Calcium toxicity
E. Molybdenum deficiency
Iron deficiency
Plant transpiration efficiency at a given location is markedly influenced by _.
A. Organic residue cover on the soil
B. Tillage practices used
C. Fertilization practices used
D. The plant species being grown
E. Both C and D
Both C and D
Groundwater _.
A. Is a source of water above the vadose zone in a soil
B. Moves downward in the vadose zone through the capillary fringe
C. Moves laterally but not vertically below the soil profile
D. Is found mostly in shallow layers just below the argillic
E. Is a major source of water for irrigation in the United States
Is a major source of water for irrigation in the United States
Forest fires result in sufficiently high soil temperatures to cause the vaporization and movement of certain organic compounds in soils. The main effect of these compounds is to _.
A. Reduce water infiltration and percolation through the profile
B. Enhance soil structural stability
C. Increase pH
D. Decrease water losses by surface runoff
E. Increase soil organic matter
Reduce water infiltration and percolation through the profile
The process of aerobic respiration is a significant source of which of the following gases?
A. Methane
B. Oxygen
C. Nitrogen
D. Carbon dioxide
E. Ammonia
Carbon dioxide
The growth of plants on sodic soils is constrained by all but one of the following:
A. Caustic influence of high pH caused by sodium carbonate and bicarbonate
B. Toxicity of bicarbonate and other anions
C. Low micronutrient availability due to high pH
D. Oxygen deficiency due to breakdown of soil structure
E. Toxicity of very high levels of calcium carbonate
Toxicity of very high levels of calcium carbonate