1. : The scientific study of soil is called:
(A) Pedology
(B) Agronomy
(C) Ecology
(D) Geology
2. : The topmost layer of soil, rich in organic matter and microorganisms, is called:
(A) Subsoil
(B) Bedrock
(C) Humus
(D) Parent material
3. : The vertical section of soil showing different layers is called:
(A) Soil strata
(B) Soil profile
(C) Soil pedon
(D) Soil horizon
4. : Which soil texture is considered the most ideal for agriculture?
(A) Sandy
(B) Clayey
(C) Loamy
(D) Silty
5. : The process of soil formation is known as:
(A) Pedogenesis
(B) Weathering
(C) Sedimentation
(D) Decomposition
6. : The soil layer composed of unweathered rock material is called:
(A) Horizon A
(B) Horizon B
(C) Horizon C
(D) Bedrock (R)
7. : Which horizon is commonly called the “zone of leaching”?
(A) Horizon A
(B) Horizon B
(C) Horizon C
(D) Horizon O
8. : Which soil type is best known for its high water-holding capacity?
(A) Sandy soil
(B) Clay soil
(C) Loamy soil
(D) Gravel soil
9. : The pH of acidic soils is usually:
(A) Above 7
(B) Equal to 7
(C) Below 7
(D) Always 10
10. : Which soil-forming factor is considered the most important?
(A) Time
(B) Climate
(C) Organisms
(D) Parent material
11. : Black soils in India are also called:
(A) Laterite soils
(B) Alluvial soils
(C) Regur soils
(D) Desert soils
12. : The capacity of soil to supply essential nutrients to plants is known as:
(A) Soil fertility
(B) Soil porosity
(C) Soil texture
(D) Soil structure
13. : The structure of soil refers to:
(A) Shape and arrangement of soil particles
(B) Color of soil
(C) Nutrient content
(D) Soil depth
14. : The measure of soil’s ability to store cations is called:
(A) Soil porosity
(B) Cation exchange capacity (CEC)
(C) Soil plasticity
(D) Soil density
15. : Which microorganism is most important for nitrogen fixation in soils?
(A) Azotobacter
(B) Rhizobium
(C) Nitrosomonas
(D) Bacillus subtilis
16. : Laterite soils are generally poor in:
(A) Iron
(B) Aluminum
(C) Nitrogen and phosphorus
(D) Silica
17. : Soil erosion by wind is most common in:
(A) Desert areas
(B) Tropical forests
(C) Coastal wetlands
(D) Tundra
18. : The bulk density of soil is defined as:
(A) Mass of soil particles / volume of soil
(B) Water content / soil volume
(C) Porosity / soil weight
(D) Root depth / soil mass
19. : Which color of soil indicates good organic matter content?
(A) Red
(B) Black or dark brown
(C) Yellow
(D) White
20. : Saline soils are characterized by:
(A) High sodium chloride content
(B) Low pH
(C) High organic matter
(D) Excessive calcium
21. : Soil porosity depends mainly on:
(A) Soil texture and structure
(B) Soil pH
(C) Soil color
(D) Soil temperature
22. : Which soil conservation practice involves plowing along the contour lines?
(A) Terrace farming
(B) Contour plowing
(C) Strip cropping
(D) Shelter belts
23. : Which soil property is most important for plant root aeration?
(A) Soil porosity
(B) Soil fertility
(C) Soil color
(D) Soil acidity
24. : The soil moisture available to plants is stored between:
(A) Saturation point and field capacity
(B) Field capacity and permanent wilting point
(C) Hygroscopic water and groundwater
(D) Only at saturation point
25. : The ultimate aim of soil conservation is to:
(A) Increase erosion
(B) Preserve soil fertility and productivity
(C) Reduce soil biodiversity
(D) Increase deforestation