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 11 of 19
- A. Soil crusting
- B. Both a & c
- C. Bulk Density
- D. Soil consistence
Explanation: Soil consistence is the soil’s resistance to deformation or mechanical manipulation at different moisture contents.
Correct answer: Soil consistence- A. Illuviation
- B. Eluviation
- C. Podzolization
- D. Laterization
Explanation: Illuviation is the downward deposition or accumulation of materials such as clay, iron and organic matter in a lower soil horizon.
Correct answer: Illuviation- A. Humification
- B. Horizonation
- C. Illuviation
- D. Calcification
Explanation: Humification is the biological and chemical transformation of raw plant and animal residues into relatively stable humus.
Correct answer: Humification- A. Man and Animals
- B. All of these
- C. Micro- organisms
- D. Higher Plants and Roots
Explanation: Biological weathering is caused by living agents, including humans and animals, plant roots, and microorganisms.
Correct answer: All of these- A. Both a and b
- B. 45.5 mol/L
- C. 55.5 mol/L
- D. none of these
Explanation: One litre of water weighs about 1000 g, and the molecular mass of H₂O is about 18 g/mol, giving 1000 ÷ 18 ≈ 55.5 mol/L.
Correct answer: 55.5 mol/L- A. 1% or less of soil volume
- B. 10% or less of soil volume
- C. 20% or less of soil volume
- D. 30% or less of soil volume
Explanation: Although root occupancy varies with crop, depth and soil conditions, roots generally occupy 1% or less of the total soil volume.
Correct answer: 1% or less of soil volume- A. Urea
- B. Ammonium sulphate
- C. Ammonium nitrate
- D. Calcium ammonium nitrate
Explanation: Ammonium sulphate produces the greatest residual acidity because nitrification of its ammonium releases acidity, while its sulphate…
Correct answer: Ammonium sulphate- A. Saline-sodic soils
- B. Sodic soils
- C. Acid soils
- D. Saline soilsSoil
Explanation: Zinc is generally more soluble and available in acid soils, whereas increasing soil pH, especially in sodic conditions, promotes its…
Correct answer: Acid soils- A. Liebig
- B. Baussingault
- C. Winogrdsky
- D. Hiltner
Explanation: Lorenz Hiltner introduced the term rhizosphere for the soil region directly influenced by plant roots and their associated microorganisms.
Correct answer: Hiltner- A. L-Value
- B. E-Value
- C. a-Value
- D. A-Value
Explanation: The E-value estimates soil phosphorus in equilibrium with the soil solution through a chemical or isotopic approach and does not require…
Correct answer: E-Value- A. 2.50 %
- B. 3.50 %
- C. 4,50 %
- D. 5.5 %
Explanation: Under the Fertilizer Control Order, DAP may contain a maximum of 2.5% total nitrogen in the form of urea.
Correct answer: 2.50 %- A. Fundamentals of soil
- B. Essenttials of soil sciences
- C. The nature and properties of soil
- D. The mechanics of soilSoil
Explanation: Nyle C. Brady is associated with the standard soil-science textbook The Nature and Properties of Soils, commonly used for introductory…
Correct answer: The nature and properties of soil213. The indicator used for the the estimation of the organic matter or organic carbon is;_________?
- A. Diphenylamine indicator
- B. Mixed indicator
- C. Both a and b
- D. None of the above
Explanation: In the Walkley-Black method, organic carbon is oxidized with potassium dichromate and the excess dichromate is titrated using…
Correct answer: Diphenylamine indicator- A. Clay minerals
- B. Amorphous silicates
- C. All of the above
- D. Iron and aluminiumoxides
Explanation: Clay minerals, amorphous silicates and iron- and aluminium oxides are all secondary minerals formed through weathering or alteration of…
Correct answer: All of the above- A. 4:1-8:1
- B. 10:1-15:1
- C. 15:1-20:1
- D. N0ne of the above
Explanation: Microbial biomass generally has a C:N ratio of roughly 5:1 to 15:1, depending on the microbial group and conditions.
Correct answer: N0ne of the above- A. Regur
- B. Ragour
- C. Montmorillosol
- D. Regosol
Explanation: Regur, or black cotton soil, is a dark calcareous soil rich in expanding montmorillonitic clay.
Correct answer: Regur- A. cm/s
- B. cm2/s
- C. cm2
- D. s/cm
Explanation: Diffusivity has dimensions of length squared divided by time because it describes how rapidly a concentration or moisture gradient…
Correct answer: cm2/s- A. Topo sequence
- B. Catena
- C. Topography
- D. Chrono sequence
Explanation: A chrono sequence contains soils formed from the same parent material under similar relief, climate and organisms but at different stages…
Correct answer: Chrono sequence219. Rhizosphere is:
- A. Area with in the roots
- B. Root surface
- C. An area of soil in from root surface to 10 cm
- D. An area of soil in immediate vicinity around root
Explanation: The rhizosphere is the narrow zone of soil immediately surrounding and influenced by plant roots.
Correct answer: An area of soil in immediate vicinity around root- A. Alkali
- B. Acid
- C. Both a & b
- D. None of the above
Explanation: Humic acid dissolves in alkaline solutions but precipitates when the solution is acidified, which is the basis for separating it from…
Correct answer: Alkali