Daily MCQ On Soil Science For Agriculture Examinations

1. Which soil texture is most likely to have the highest water retention capacity?

• a) Sandy
• b) Silty
• c) Clayey
• d) Loamy

2. What is the effect of high bulk density on root growth?

• a) Enhances root growth
• b) Inhibits root penetration
• c) No effect on roots
• d) Promotes nutrient uptake

3. Which soil structure is most beneficial for agricultural production?

• a) Platy
• b) Blocky
• c) Granular
• d) Massive

4. How does particle density differ from bulk density?

• a) Particle density includes pore space
• b) Bulk density excludes organic matter
• c) Particle density measures solid particles only
• d) Bulk density measures mineral content only

5. Which factor primarily influences soil porosity?

• a) Soil texture
• b) Soil color
• c) Soil pH
• d) Soil age

6. Calculate the bulk density of soil with a mass of 1.2 kg and volume of 1.0 L.

• a) 0.8 g/cm³
• b) 1.2 g/cm³
• c) 1.0 g/cm³
• d) 1.5 g/cm³

7. What is the primary role of cation exchange capacity (CEC) in soil?

• a) Water retention
• b) Nutrient availability
• c) Soil aeration
• d) Soil temperature

8. Which soil pH range is considered optimal for most crop growth?

• a) 4.5 to 5.5
• b) 5.5 to 7.0
• c) 6.0 to 7.5
• d) 7.5 to 8.5

9. What is the impact of high soil organic matter on nutrient availability?

• a) Decreases nutrient retention
• b) Increases nutrient leaching
• c) Enhances nutrient release
• d) No impact on nutrients

10. Which microorganism is primarily responsible for nitrogen fixation in soil?

• a) Rhizobium
• b) Pseudomonas
• c) Bacillus
• d) Aspergillus

11. What process involves the breakdown of organic matter in soil?

• a) Mineralization
• b) Immobilization
• c) Humification
• d) Deamination

12. Which nutrient is most likely to be deficient in highly weathered tropical soils?

• a) Nitrogen
• b) Phosphorus
• c) Potassium
• d) Calcium

13. Which soil amendment is used to raise soil pH?

• a) Gypsum
• b) Lime
• c) Sulfur
• d) Compost

14. What is the main benefit of using cover crops in soil management?

• a) Increase soil temperature
• b) Improve soil structure
• c) Enhance soil compaction
• d) Reduce soil porosity

15. Which irrigation method minimizes water loss through evaporation?

• a) Surface irrigation
• b) Drip irrigation
• c) Sprinkler irrigation
• d) Furrow irrigation

16. What is the purpose of soil drainage systems in agricultural fields?

• a) Increase soil acidity
• b) Prevent waterlogging
• c) Enhance soil fertility
• d) Decrease soil temperature

17. Which process is used to remove salts from saline soils?

• a) Salinization
• b) Leaching
• c) Compaction
• d) Acidification

18. How does soil pH affect the availability of micronutrients?

• a) Low pH increases availability
• b) High pH increases availability
• c) Neutral pH decreases availability
• d) pH has no effect

19. Which practice can help reduce soil erosion in hilly areas?

• a) Monoculture farming
• b) Terrace farming
• c) Slash and burn
• d) Clear cutting

20. What is the role of gypsum in soil management?

• a) Increase soil acidity
• b) Improve soil structure
• c) Enhance soil porosity
• d) Reduce soil compaction

21. Which soil microorganism group is primarily involved in decomposition?

• a) Fungi
• b) Bacteria
• c) Algae
• d) Protozoa

22. Which nutrient is most commonly associated with chlorosis in plants?

• a) Iron
• b) Magnesium
• c) Calcium
• d) Nitrogen

23. Which soil conservation practice involves the planting of trees along contours?

• a) Agroforestry
• b) Alley cropping
• c) Windbreaks
• d) Shelterbelts

24. What is the effect of high sodium concentration on soil structure?

• a) Increases soil fertility
• b) Enhances soil aggregation
• c) Promotes soil crusting
• d) Reduces soil porosity

25. What is the primary function of mycorrhizae in soil ecosystems?

• a) Fix nitrogen
• b) Enhance phosphorus uptake
• c) Decompose organic matter
• d) Control soil pests

26. Which type of erosion is characterized by the formation of small channels?

• a) Sheet erosion
• b) Rill erosion
• c) Gully erosion
• d) Wind erosion

27. How do conservation tillage practices benefit soil health?

• a) Increase soil compaction
• b) Reduce soil erosion
• c) Decrease soil moisture retention
• d) Lower soil organic matter

28. Which soil property is directly influenced by soil organic matter?

• a) Soil color
• b) Soil texture
• c) Soil structure
• d) Soil mineral content

29. What is the primary cause of waterlogging in agricultural fields?

• a) Excessive rainfall
• b) Poor drainage
• c) Low soil fertility
• d) High soil temperature

30. Which soil amendment is used to improve saline soil conditions?

• a) Sulfur
• b) Gypsum
• c) Lime
• d) Urea

31. How does soil compaction affect root growth?

• a) Promotes root branching
• b) Inhibits root penetration
• c) Enhances nutrient uptake
• d) Reduces root hair formation

32. Which practice helps improve soil aeration?

• a) Heavy machinery use
• b) Soil compaction
• c) Organic matter addition
• d) Over-irrigation

33. What is the impact of high levels of aluminum in acidic soils?

• a) Increases pH
• b) Toxic to plant roots
• c) Enhances nutrient uptake
• d) Improves soil structure

34. Calculate the cation exchange capacity (CEC) of a soil sample with 5 meq/100g of Ca²⁺, 3 meq/100g of Mg²⁺, and 2 meq/100g of K⁺.

• a) 8 meq/100g
• b) 10 meq/100g
• c) 12 meq/100g
• d) 15 meq/100g

35. Which factor most influences soil infiltration rates?

• a) Soil temperature
• b) Soil moisture content
• c) Soil texture
• d) Soil color

36. Which soil component primarily determines its buffering capacity?

• a) Sand content
• b) Organic matter
• c) Clay minerals
• d) Soil water

37. What is the main advantage of bioremediation in soil management?

• a) Quick results
• b) Cost-effectiveness
• c) Non-invasive approach
• d) High chemical use

38. Which element is critical for nitrogen fixation in legumes?

• a) Phosphorus
• b) Iron
• c) Molybdenum
• d) Calcium

39. How does soil organic matter contribute to soil fertility?

• a) Increases soil erosion
• b) Enhances nutrient availability
• c) Decreases water retention
• d) Reduces microbial activity

40. What is the primary purpose of green manure in agriculture?

• a) Increase soil compaction
• b) Enhance soil nutrients
• c) Raise soil temperature
• d) Reduce soil pH

41. Which soil amendment is commonly used to improve clay soil structure?

• a) Sand
• b) Peat
• c) Compost
• d) Lime

42. How does salinity affect plant growth in agricultural soils?

• a) Enhances root absorption
• b) Increases water uptake
• c) Causes osmotic stress
• d) Improves leaf expansion

43. Which method is effective for preventing nutrient leaching in sandy soils?

• a) Frequent irrigation
• b) Deep plowing
• c) Cover cropping
• d) Heavy fertilization

44. What is the role of earthworms in soil health?

• a) Compaction of soil
• b) Decomposition of organic matter
• c) Fixation of nitrogen
• d) Reduction of soil pH

45. Which soil pH range is optimal for most plant growth?

• a) 4.0 – 5.0
• b) 5.5 – 6.5
• c) 6.0 – 7.0
• d) 7.5 – 8.5

46. How does soil compaction influence water infiltration?

• a) Increases infiltration rate
• b) Reduces infiltration rate
• c) Has no effect
• d) Enhances water retention

47. Which organic matter addition is known to enhance microbial activity in soils?

• a) Biochar
• b) Manure
• c) Peat moss
• d) Sand

48. What is the primary advantage of crop rotation in soil management?

• a) Increase soil acidity
• b) Enhance nutrient cycling
• c) Improve soil texture
• d) Reduce soil moisture

49. Which factor contributes to the formation of acidic soils?

• a) High pH
• b) Low rainfall
• c) Leaching of bases
• d) Presence of lime

50. What is the significance of soil texture in agriculture?

• a) Determines soil pH
• b) Affects water retention
• c) Influences nutrient content
• d) Controls soil temperature