OSSF TEST PRACTICE EXAM | QUESTIONS AND ANSWERS |
VERIFIED ANSWERS GRADED A+ | LATEST EXAM
1. Which soil property primarily determines water retention capacity?
A) Texture
B) Color
C) Temperature
D) Structure
Answer: A) Texture
2. Loam soil is considered ideal for plant growth because it has:
A) High sand content only
B) Balanced sand, silt, and clay content
C) Very high clay content
D) Only silt and clay
Answer: B) Balanced sand, silt, and clay content
3. The process by which soil aggregates are broken down by water is called:
A) Erosion
B) Leaching
C) Soil compaction
D) Crusting
Answer: A) Erosion
4. The soil horizon rich in organic matter is labeled as:
A) A
B) B
C) C
D) R
Answer: A) A
5. Which soil type has the highest infiltration rate?
A) Clay
B) Silt
C) Sand
D) Loam
Answer: C) Sand
,6. Which factor has the least influence on soil formation?
A) Parent material
B) Climate
C) Soil color
D) Organisms
Answer: C) Soil color
7. Soil pH below 5.5 is classified as:
A) Neutral
B) Acidic
C) Alkaline
D) Saline
Answer: B) Acidic
8. Which soil particle size is smallest?
A) Sand
B) Silt
C) Clay
D) Gravel
Answer: C) Clay
9. A soil with poor drainage and high water table is classified as:
A) Well-drained
B) Moderately drained
C) Poorly drained
D) Saturated
Answer: C) Poorly drained
10. Soil color red or yellow usually indicates high:
A) Organic matter
B) Iron oxides
C) Calcium carbonate
D) Sodium content
Answer: B) Iron oxides
11. Soil bulk density is inversely related to:
A) Porosity
B) Texture
C) Color
D) Structure
Answer: A) Porosity
,12. The term “field capacity” refers to:
A) Soil moisture after saturation
B) Maximum water soil can hold against gravity
C) Point of permanent wilting
D) Dry soil moisture content
Answer: B) Maximum water soil can hold against gravity
13. Clay soils are prone to:
A) Rapid infiltration
B) Waterlogging and slow drainage
C) Nutrient leaching
D) Low compaction
Answer: B) Waterlogging and slow drainage
14. The main cation exchange in soil involves:
A) Na⁺, K⁺, Ca²⁺, Mg²⁺
B) Cl⁻, NO₃⁻, SO₄²⁻
C) H₂O molecules
D) CO₃²⁻
Answer: A) Na⁺, K⁺, Ca²⁺, Mg²⁺
15. Soil structure described as “blocky” is typical in:
A) O horizon
B) A horizon
C) B horizon
D) R horizon
Answer: C) B horizon
16. The term “loess” refers to:
A) Wind-deposited silt
B) Volcanic ash soil
C) Clay-rich soil
D) Organic-rich soil
Answer: A) Wind-deposited silt
17. The main cause of soil salinization is:
A) Excess rainfall
B) Irrigation with saline water
C) Leaching
D) Organic matter accumulation
Answer: B) Irrigation with saline water
, 18. Soil permeability is directly related to:
A) Clay content
B) Organic matter
C) Porosity
D) pH
Answer: C) Porosity
19. Soil texture triangle divides soil into:
A) 3 horizons
B) Sand, silt, clay percentages
C) Organic, mineral, rock
D) Acidic, neutral, alkaline
Answer: B) Sand, silt, clay percentages
20. The term “perched water table” describes:
A) Water table at bedrock
B) Local saturated zone above main water table
C) Water table in a riverbed
D) Deep groundwater
Answer: B) Local saturated zone above main water table
21. Which soil order is typical of tropical regions with high weathering?
A) Alfisols
B) Oxisols
C) Mollisols
D) Gelisols
Answer: B) Oxisols
22. Soil erosion by water is accelerated by:
A) Vegetative cover
B) Slope gradient
C) Mulching
D) Contour farming
Answer: B) Slope gradient
23. Which method measures soil moisture directly?
A) Gravimetric method
B) Neutron probe
C) Tensiometer
D) Capacitance sensor
Answer: A) Gravimetric method
VERIFIED ANSWERS GRADED A+ | LATEST EXAM
1. Which soil property primarily determines water retention capacity?
A) Texture
B) Color
C) Temperature
D) Structure
Answer: A) Texture
2. Loam soil is considered ideal for plant growth because it has:
A) High sand content only
B) Balanced sand, silt, and clay content
C) Very high clay content
D) Only silt and clay
Answer: B) Balanced sand, silt, and clay content
3. The process by which soil aggregates are broken down by water is called:
A) Erosion
B) Leaching
C) Soil compaction
D) Crusting
Answer: A) Erosion
4. The soil horizon rich in organic matter is labeled as:
A) A
B) B
C) C
D) R
Answer: A) A
5. Which soil type has the highest infiltration rate?
A) Clay
B) Silt
C) Sand
D) Loam
Answer: C) Sand
,6. Which factor has the least influence on soil formation?
A) Parent material
B) Climate
C) Soil color
D) Organisms
Answer: C) Soil color
7. Soil pH below 5.5 is classified as:
A) Neutral
B) Acidic
C) Alkaline
D) Saline
Answer: B) Acidic
8. Which soil particle size is smallest?
A) Sand
B) Silt
C) Clay
D) Gravel
Answer: C) Clay
9. A soil with poor drainage and high water table is classified as:
A) Well-drained
B) Moderately drained
C) Poorly drained
D) Saturated
Answer: C) Poorly drained
10. Soil color red or yellow usually indicates high:
A) Organic matter
B) Iron oxides
C) Calcium carbonate
D) Sodium content
Answer: B) Iron oxides
11. Soil bulk density is inversely related to:
A) Porosity
B) Texture
C) Color
D) Structure
Answer: A) Porosity
,12. The term “field capacity” refers to:
A) Soil moisture after saturation
B) Maximum water soil can hold against gravity
C) Point of permanent wilting
D) Dry soil moisture content
Answer: B) Maximum water soil can hold against gravity
13. Clay soils are prone to:
A) Rapid infiltration
B) Waterlogging and slow drainage
C) Nutrient leaching
D) Low compaction
Answer: B) Waterlogging and slow drainage
14. The main cation exchange in soil involves:
A) Na⁺, K⁺, Ca²⁺, Mg²⁺
B) Cl⁻, NO₃⁻, SO₄²⁻
C) H₂O molecules
D) CO₃²⁻
Answer: A) Na⁺, K⁺, Ca²⁺, Mg²⁺
15. Soil structure described as “blocky” is typical in:
A) O horizon
B) A horizon
C) B horizon
D) R horizon
Answer: C) B horizon
16. The term “loess” refers to:
A) Wind-deposited silt
B) Volcanic ash soil
C) Clay-rich soil
D) Organic-rich soil
Answer: A) Wind-deposited silt
17. The main cause of soil salinization is:
A) Excess rainfall
B) Irrigation with saline water
C) Leaching
D) Organic matter accumulation
Answer: B) Irrigation with saline water
, 18. Soil permeability is directly related to:
A) Clay content
B) Organic matter
C) Porosity
D) pH
Answer: C) Porosity
19. Soil texture triangle divides soil into:
A) 3 horizons
B) Sand, silt, clay percentages
C) Organic, mineral, rock
D) Acidic, neutral, alkaline
Answer: B) Sand, silt, clay percentages
20. The term “perched water table” describes:
A) Water table at bedrock
B) Local saturated zone above main water table
C) Water table in a riverbed
D) Deep groundwater
Answer: B) Local saturated zone above main water table
21. Which soil order is typical of tropical regions with high weathering?
A) Alfisols
B) Oxisols
C) Mollisols
D) Gelisols
Answer: B) Oxisols
22. Soil erosion by water is accelerated by:
A) Vegetative cover
B) Slope gradient
C) Mulching
D) Contour farming
Answer: B) Slope gradient
23. Which method measures soil moisture directly?
A) Gravimetric method
B) Neutron probe
C) Tensiometer
D) Capacitance sensor
Answer: A) Gravimetric method
