Soils of India — Set 2

Correct Answer: A. Forest Soil

• **Forest/Mountain soil** = found in Himalayan forest regions, loamy and silty in valleys, coarse-grained on upper slopes. • **Valley sides vs upper slopes** — the key contrast in forest soil: fertile loamy in lower valleys, acidic coarse on upper slopes. • 💡 Wrong-option analysis: Saline soil: high salt content, arid/coastal areas, not Himalayan forests; Laterite soil: high-rainfall plateaus of Western/Eastern Ghats; Black soil: Deccan Trap volcanic region, not Himalayas.

Correct Answer: C. Usara

• **Saline soil = Usara** = also called Usara or Reh/Kallar, containing high proportions of sodium, potassium, and magnesium, infertile. • **Sodium, potassium, magnesium excess** — the mineral imbalance in saline/Usara soil that prevents plant growth. • 💡 Wrong-option analysis: Bhangar: old alluvium sub-type; Regur: another name for black soil; Kankar: calcium carbonate nodules within Bhangar layer.

Correct Answer: C. Black Soil

• **Black soil in Malwa Plateau** = the Malwa Plateau is covered by black soil due to its volcanic Deccan Trap origin; cotton and soyabean are major crops. • **Volcanic Deccan Trap origin** — the basaltic rock parent material that gives Malwa Plateau its characteristic black soil. • 💡 Wrong-option analysis: Alluvial soil: Indo-Gangetic plains, not Malwa; Laterite soil: Western/Eastern Ghats high-rainfall areas; Red soil: eastern and southern Deccan, not Malwa.

Correct Answer: A. Terrace Farming

• **Terrace farming** = primary practice to prevent soil erosion in hilly areas by creating flat steps on steep slopes to slow water runoff. • **Himalayan states** — where terrace farming is most extensively practiced to conserve soil on steep hill slopes. • 💡 Wrong-option analysis: Mixed Cropping: grows multiple crops together, doesn't specifically prevent erosion; Monoculture: single-crop intensive farming, actually increases erosion risk; Strip Cropping: alternate strips of crops and grass on flat land.

Correct Answer: A. Nitrogen

• **Nitrogen deficiency** = the most common and widespread nutrient deficiency across almost all Indian soil types. • **Urea usage** — the widespread use of urea (nitrogenous fertilizer) in Indian agriculture reflects the universal nitrogen deficiency. • 💡 Wrong-option analysis: Magnesium: deficiency is not universal; black soil is actually rich in it; Potash: alluvial soil is rich in potash; Iron: red soil is rich in iron.

Correct Answer: C. Alluvial Soil

• **Alluvial soil in eastern coast deltas** = the deltas of Mahanadi, Godavari, Krishna, and Kaveri rivers are composed of rich alluvial soil ideal for rice. • **Mahanadi-Godavari-Krishna-Kaveri deltas** — the four major delta systems on the eastern coast contributing rich alluvial soil. • 💡 Wrong-option analysis: Peaty soil: found in coastal waterlogged areas, different from delta alluvium; Arid soil: found in dry Rajasthan/NW India, not eastern coast; Black soil: Deccan Trap region, not coastal deltas.

Correct Answer: B. Gujarat

• **Gujarat** = has the largest area of saline soils in India due to the Rann of Kutch and coastal saltwater ingress. • **Rann of Kutch** — India's largest salt desert, contributing massively to Gujarat's saline soil coverage. • 💡 Wrong-option analysis: Uttar Pradesh: has some saline/Usar soil but smaller area; Rajasthan: has arid/desert soil but less saline than Gujarat; Maharashtra: black soil dominant, not saline.

Correct Answer: D. Calcium Carbonate nodules

• **Kankar = Calcium Carbonate nodules** = small, irregular CaCO3 deposits found in the Bhangar (old alluvium) layer, indicating lower fertility. • **Lower fertility indicator** — Kankar's presence in Bhangar signals older, less fertile alluvium compared to Khadar. • 💡 Wrong-option analysis: Organic Humus: found in forest/peaty soils, not specifically called Kankar; Iron nodules: found in laterite soil; Volcanic ash: parent material for black soil, not Kankar.

Correct Answer: A. Laterite Soil

• **Laterite soil** = best suited for tea, coffee, and rubber in the Western Ghats due to its acidic nature and high-rainfall origin. • **Acidic nature supports plantation crops** — tea and coffee thrive in acidic laterite soil despite it being nutrient-poor for regular crops. • 💡 Wrong-option analysis: Alluvial soil: ideal for grains/cereals, not specifically for plantation crops; Black soil: alkaline/neutral, not acidic, doesn't suit tea/coffee; Arid soil: alkaline, dry, completely unsuitable for tea/coffee.

Correct Answer: D. Eight

• **Eight major soil groups (ICAR)** = alluvial, black, red and yellow, laterite, arid, saline, peaty, and forest soils. • **ICAR classification** — the scientific basis for managing India's diverse agricultural soils through this 8-group system. • 💡 Wrong-option analysis: Seven: one less than the actual number; Six: too few; Nine: one more than actual ICAR count of eight.