Free Soil Science MCQs with Answers
377 Soil Science MCQs from Agriculture, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Last updated
377 questions · page 2 of 19
- A. Black soils
- B. River soils
- C. Marine deposits
- D. Both B & c
Explanation: Vertisols are dark, clay-rich soils that commonly correspond to black soils or black cotton soils.
Correct answer: Black soils- A. Prismatic & Columnar
- B. Spheroidal or Sphere-like
- C. Angular blocky Sub-angular blocky
- D. Platy & Luminar
Explanation: Grassland soils usually develop granular or spheroidal aggregates because dense grass roots and organic matter promote crumb formation.
Correct answer: Spheroidal or Sphere-like- A. Cutting trees
- B. Excessive grazing
- C. By plantation
- D. By heavy irrigation
Explanation: Plantation protects soil by reducing the direct impact of raindrops, slowing runoff and binding soil with roots.
Correct answer: By plantation- A. Saltation
- B. Rainsplash erosion
- C. Sheet erosion
- D. Rill erosionExplore Farming Tools
Explanation: Saltation is classically a mode of wind erosion in which particles bounce along the surface, whereas rainsplash, sheet and rill erosion…
Correct answer: Saltation- A. E
- B. B
- C. O
- D. A
Explanation: Wash-in, or illuviation, is the downward accumulation of materials such as clay, iron and organic matter in the B horizon.
Correct answer: B- A. Stone
- B. Soil
- C. Silt
- D. Rock
Explanation: Soil texture is determined by the relative proportions of sand, silt and clay.
Correct answer: Silt- A. Soil Salinity
- B. Soil Pollution
- C. Soil Quality
- D. None of theseSoil
Explanation: Soil quality is the soil’s capacity to perform ecological functions sustainably, including supporting plant and animal health.
Correct answer: Soil Quality- A. All of the above
- B. Crops & fodder grown on polluted soil may pass the pollutants on to the consumers
- C. Soil structure is damaged or polluted soil may no longer grow crops & fodder
- D. Pollution runs-off into rivers & kills the fish, plant & other aquatic life
Explanation: Soil pollution can contaminate runoff and aquatic life, transfer pollutants through crops and fodder to consumers, and damage soil…
Correct answer: All of the above- A. Arsenic & Cadmium
- B. Both A & B
- C. Calcium & Magnesium
- D. Mercury & chromium
Explanation: Arsenic, cadmium, mercury and chromium are toxic inorganic contaminants that can threaten human, animal and plant health.
Correct answer: Both A & B- A. Lead
- B. Fluorine
- C. All of the above
- D. Nickle
Explanation: Lead, fluorine and nickel are commonly listed among moderately toxic inorganic soil contaminants in basic environmental-pollution…
Correct answer: All of the above- A. None of the aboveSoil
- B. Neutral rain
- C. Both A & B
- D. Acid rain
Explanation: Sulfur dioxide and nitrogen oxides form sulfuric and nitric acids in atmospheric moisture.
Correct answer: Acid rain- A. The plant absorbs carbon as carbondioxides directly from the atmosphere.
- B. All of the above
- C. Air & water is the source of oxygen & the chief source of soil nitrogen is organic matter & when organic matter decomposes it gives ammonia.
- D. Water is the source of hydrogen
Explanation: Plants obtain carbon mainly from atmospheric carbon dioxide, hydrogen from water, and oxygen from air and water.
Correct answer: All of the above- A. Mg
- B. N
- C. P
- D. None of the above
Explanation: Phosphorus becomes strongly fixed by soil minerals, particularly iron, aluminium and calcium compounds, so it moves very little in soil.
Correct answer: P- A. pH decrease, Ec increase
- B. pH & Ec both increase
- C. None of these
- D. pH increase & Ec decrease
Explanation: Leaching a saline-alkaline soil removes soluble salts, so its electrical conductivity decreases; removal of soluble salts also allows…
Correct answer: pH increase & Ec decrease- A. Non-symbiotically
- B. Symbiotically
- C. Can fix A & B
- D. None of these
Explanation: Azotobacter is a free-living nitrogen-fixing bacterium that fixes atmospheric nitrogen independently in the soil, without forming root…
Correct answer: Non-symbiotically- A. 1:1 clay mineral
- B. 1:2 clay mineral
- C. 2:1 clay mineral
- D. 2:2 clay mineral
Explanation: Potassium fixation is greatest in expanding 2:1 clay minerals, especially illite and vermiculite, where K⁺ becomes trapped between mineral…
Correct answer: 2:1 clay mineral- A. Mineralization
- B. both A & C
- C. Solubilization
- D. Immobilization
Explanation: Immobilization is the microbial conversion of inorganic phosphorus into organic forms, temporarily reducing its availability to plants.
Correct answer: Immobilization- A. 2
- B. 4
- C. 6
- D. 5Search Public Records
Explanation: Soil colloids are broadly classified into two groups: inorganic colloids, mainly clay minerals and oxides, and organic colloids, chiefly…
Correct answer: 2- A. Onsite damages
- B. Both A & B
- C. Offsite damages
- D. None of the above
Explanation: Soil erosion causes onsite damage by removing fertile topsoil and nutrients, while offsite damage includes siltation and water pollution.
Correct answer: Both A & B- A. Permanent gullies
- B. Both A & B
- C. Ephemeral gullies
- D. None of these
Explanation: Ephemeral gullies are shallow channels that form repeatedly in natural depressions but can usually be erased by normal tillage.
Correct answer: Ephemeral gullies