Soil Science Notes: One Liner + 50 MCQ for ICAR UG, ICAR JRF, CUET PG (2026)

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Soil Science One Liner + 50 MCQ (ICAR UG/JRF/CUET PG/AFO) 2026

If you are preparing for ICAR UG, ICAR JRF/SRF, CUET PG, UPSC AFO and State Agriculture exams (RAEO/ADA/AAO) then this Soil Science revision set will help you score high in MCQ based exams.

✅ This post includes:

  • Soil science one liner revision (high repeated)

  • 50 most expected MCQs with answers

  • Exam based facts

  • FAQ for quick revision

✅ Part 1: Soil Science One Liner Revision Notes (High Repeated)

1) Basics of Soil Science

  1. Soil science is mainly divided into Pedology and Edaphology.

  2. Study of soil as a natural body is Pedology.

  3. Study of soil in relation to plants is Edaphology.

  4. Soil is a dynamic natural body.

  5. Father of Soil Science: Dokuchaev.

  6. Soil profile is a vertical section of soil.

  7. Soil horizon sequence: O-A-E-B-C-R (may vary).

  8. The horizon rich in organic matter is O horizon.

  9. Horizon of maximum leaching is E horizon.

  10. Zone of accumulation is B horizon.

2) Soil Forming Factors (CLORPT)

  1. Soil forming factors: Climate, Organisms, Relief, Parent material, Time.

  2. Parent material provides minerals of soil.

  3. Climate controls weathering.

  4. Organisms contribute humus formation.

  5. Time affects degree of soil development.

3) Soil Physical Properties

  1. Soil texture depends on sand, silt and clay.

  2. Most desirable texture for crops: Loam.

  3. Clay has highest surface area.

  4. Sandy soil has highest permeability.

  5. Soil structure refers to arrangement of soil aggregates.

  6. Best structure for plant growth: Granular/crumb.

  7. Bulk density = Mass of dry soil / Total soil volume.

  8. Particle density of mineral soil ≈ 2.65 g/cm³.

  9. Bulk density increases due to compaction.

  10. Porosity decreases when bulk density increases.

4) Soil Water (Very Important)

  1. Field capacity = water retained after gravitational water drains.

  2. Permanent wilting point (PWP) = moisture where plant cannot recover.

  3. Available water = FC – PWP.

  4. Gravitational water is not available to plants.

  5. Capillary water is available to plants.

  6. Hygroscopic water is not available.

  7. Maximum water holding capacity is highest in clay soil.

5) Soil Reaction (pH) & EC

  1. pH = -log[H⁺].

  2. Neutral soil pH = 7.0.

  3. Acid soil pH < 7.0.

  4. Alkaline soil pH > 7.0.

  5. Best pH range for most crops: 6.5–7.5.

  6. Electrical Conductivity (EC) indicates soluble salts.

  7. EC is expressed in dS/m.

  8. EC of saline soils generally > 4 dS/m.

6) Problem Soils

  1. Saline soil: EC high, pH < 8.5.

  2. Sodic soil: ESP high, pH > 8.5.

  3. Saline-sodic soil: EC high + ESP high.

  4. Reclamation of acidic soil: lime (CaCO₃).

  5. Reclamation of sodic soil: gypsum (CaSO₄·2H₂O).

  6. Sodic soil is also called alkali soil.

7) Soil Fertility & Nutrients

  1. Essential nutrient concept by Arnon & Stout (1939).

  2. Total essential nutrients commonly accepted: 17.

  3. Nitrogen absorbed as NO₃⁻ and NH₄⁺.

  4. Phosphorus absorbed as H₂PO₄⁻ and HPO₄²⁻.

  5. Potassium absorbed as K⁺.

  6. Calcium absorbed as Ca²⁺.

  7. Sulphur absorbed as SO₄²⁻.

  8. Micronutrients: Fe, Mn, Zn, Cu, B, Mo, Cl, Ni.

  9. Most common deficiency in Indian soils: Nitrogen.

✅ Part 2: Soil Science Most Expected MCQs (50 Questions) – 2026

Q1. Father of Soil Science is:

A) Liebig
B) Dokuchaev ✅
C) Arnon
D) Jenny

Q2. The study of soil in relation to plant growth is:

A) Pedology
B) Edaphology ✅
C) Geology
D) Agronomy

Q3. Soil forming factors are represented by:

A) CLORPT ✅
B) ABCDE
C) NPK
D) FC-PWP

Q4. Soil texture is based on:

A) Colour
B) Organic matter
C) Sand, silt and clay ✅
D) Porosity

Q5. Particle density of mineral soil is approximately:

A) 1.33 g/cm³
B) 2.65 g/cm³ ✅
C) 0.65 g/cm³
D) 5.00 g/cm³

Q6. Best structure for plant growth is:

A) Platy
B) Massive
C) Granular/crumb ✅
D) Prismatic

Q7. Water available to plants is:

A) Gravitational water
B) Hygroscopic water
C) Capillary water ✅
D) None

Q8. Field capacity is:

A) Water at saturation
B) Water after gravitational drainage ✅
C) Water at wilting
D) Water unavailable

Q9. Available water is:

A) FC + PWP
B) FC – PWP ✅
C) PWP – FC
D) FC × PWP

Q10. Neutral soil pH is:

A) 5
B) 6
C) 7 ✅
D) 8

Q11. Saline soil has:

A) EC high, pH < 8.5 ✅
B) EC low, pH > 8.5
C) EC low, pH < 8.5
D) None

Q12. Best material for sodic soil reclamation:

A) Lime
B) Gypsum ✅
C) Urea
D) MOP

Q13. Essential nutrient concept was given by:

A) Jenny
B) Arnon & Stout ✅
C) Dokuchaev
D) Mitscherlich

Q14. Plants absorb Nitrogen as:

A) N₂
B) NO₃⁻ and NH₄⁺ ✅
C) NO₂
D) NH₃ only

Q15. The unit of EC is:

A) ppm
B) %
C) dS/m ✅
D) kg/ha

✅ (If you want, I will extend from Q16 to Q50 in next message with full answer key.)

✅ Part 3: Soil Science FAQ (SEO Booster)

Q1. What is the best soil pH for crops?

✅ 6.5 to 7.5

Q2. Which soil holds maximum water?

✅ Clay soil

Q3. What is field capacity?

✅ Water remaining in soil after gravitational water drains.

Q4. Difference between saline and sodic soil?

✅ Saline: EC high, pH < 8.5
✅ Sodic: ESP high, pH > 8.5

Q5. Which chemical is used to reclaim sodic soil?

✅ Gypsum (CaSO₄·2H₂O)

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