Free Soil Science MCQs with Answers

• A. Both A & B
• B. Biochar
• C. Black C
• D. None of the above

Explanation: Charcoal is a carbon-rich black material and is commonly termed black carbon; when produced or applied specifically for soil improvement…

• A. Accelerated activities
• B. Over grazing
• C. Dry farming agriculture
• D. None of the aboveExplore Farming Tools

Explanation: Overgrazing removes protective vegetation and exposes soil to wind and water erosion, making it a major direct cause of desertification.

• A. Wind erosion
• B. Rainfall
• C. land sliding
• D. None of these

Explanation: Deforestation reduces evapotranspiration and can lower local or regional rainfall.

• A. Tillage
• B. Tiller
• C. Tilth
• D. None of these

Explanation: Tilth describes the physical condition of soil, including its structure, looseness, aggregation and suitability for seed germination and…

• A. Clay soil
• B. Sandy soil
• C. All of theseGeology
• D. Peat soil

Explanation: Peat soil is an organic soil formed from accumulated, partly decomposed plant material, generally containing more than 50% organic matter.

• A. Earth
• B. Land
• C. Soil
• D. fragmented rock

Explanation: In traditional terminology, civil engineers commonly use “earth” for the soil or unconsolidated material involved in construction and…

• A. Primary orthophosphate
• B. Secondary orthophosphate
• C. both
• D. None of these

Explanation: In alkaline soil, phosphate exists predominantly as the divalent secondary orthophosphate ion, HPO₄²⁻.

• A. Both
• B. Secondary orthophosphate
• C. Primary orthophosphate
• D. None of theseHire Grant Writers

Explanation: Acidic soils favour the primary orthophosphate ion, H₂PO₄⁻, which is one of the principal forms absorbed by plant roots.

• A. Both
• B. HPO4-2
• C. H2po4
• D. Non of theseAccess Government Careers

Explanation: Plants take up phosphorus mainly as the inorganic phosphate ions H₂PO₄⁻ and HPO₄²⁻.

• A. Low organic matter
• B. High organic matter
• C. Both a & b
• D. None of these

Explanation: Forest soils usually contain more organic matter from leaf litter and decomposed residues.

• A. Mull
• B. Mycorrhizae
• C. Mulch
• D. Muck

Explanation: Mulch is any material spread on the soil surface to reduce evaporation, erosion, crusting, temperature extremes, and weed growth.

• A. Suitable for grazing
• B. Suitable for forestry
• C. Unsuitable for any agricultural use
• D. Suitable for cultivated farming

Explanation: Land capability classes I to IV have limitations ranging from slight to severe, but they can still support cultivated farming with…

• A. Foliated metamorphic rocks
• B. Both a & b
• C. Non-foliated metamorphic rocks
• D. None of a & bExplore Farming Tools

Explanation: Metamorphic rocks are grouped by texture into foliated rocks, which show mineral layering, and non-foliated rocks, which do not.

• A. Sedimentary rocks
• B. Secondary rocks
• C. All of the above
• D. Aqueous rocks

Explanation: When primary rocks are transported and deposited, then compacted and cemented, they form sedimentary rocks.

• A. None of the aboveFind Geological Maps
• B. Secondary rocks
• C. Aqueous rocks
• D. Primary rocks

Explanation: Igneous rocks form first from the cooling and solidification of molten magma or lava, so they are traditionally called primary rocks.

• A. All of the above
• B. Oxygen
• C. Carbon dioxide
• D. Nitrogen

Explanation: Soil air occupies the pore spaces not filled with water and contains nitrogen, oxygen, carbon dioxide, and water vapour.

• A. Solids
• B. Liquids
• C. All of the above
• D. Gases

Explanation: Soil is a three-phase system consisting of solid mineral and organic matter, liquid soil water, and gaseous soil air.

• A. Carbonation
• B. Acidification
• C. Dissolution
• D. Hydration

Explanation: Hydration is the chemical weathering process in which minerals incorporate water into their structure, causing expansion and weakening.

• A. Aridisols
• B. Gelisols
• C. Endsols
• D. None of the aboveHire Grant Writers

Explanation: Volcanic soils are classified chiefly as Andisols, also called Andosols in some systems.

• A. Young soils with few horizons
• B. Volcanic soils
• C. Organic soils
• D. Dry soils

Explanation: Inceptisols are relatively young soils showing the early development of diagnostic horizons, but they are more developed than Entisols.