Soil Science MCQs 25 Score: 0 Attempted: 0/25 Subscribe 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