✅ Answer: A) 1, 2 and 3All three statements are correct. Black soil (Regur) is formed from the weathering of Deccan Trap (volcanic lava). Laterite soil is formed by leaching — heavy rainfall washes away silica and lime. Alluvial soil is the most widespread soil in India, covering ~43% of the total land area.

✅ Answer: B) Black soil (Cotton soil)Regur is another name for black soil (also called Cotton soil). The word “Regur” is derived from the Telugu word “Reguda” meaning black. It is found in the Deccan Plateau — Maharashtra, Madhya Pradesh, Gujarat, and parts of Andhra Pradesh. It is best suited for cotton cultivation due to its high moisture retention capacity.

✅ Answer: C) Red soilRed soil is most suitable for growing groundnuts. Red soil is porous and well-drained, which is ideal for groundnut cultivation (groundnuts need well-drained soil). Red soil is found in Tamil Nadu, Andhra Pradesh, Karnataka, and Odisha — the major groundnut-producing states. Millets, tobacco, and fruits also grow well in red soil.

✅ Answer: B) Calcium carbonate nodulesKankar is calcium carbonate (CaCO₃) nodules found in Bhangar soil (old alluvium). These nodules form when calcium carbonate precipitates from groundwater. Kankar makes the soil less fertile and harder to cultivate. Bhangar soil with Kankar is less fertile than Khadar (new alluvium) which does not contain Kankar.

✅ Answer: C) Western Ghats and Northeast IndiaLaterite soil is found in the Western Ghats (Kerala, Karnataka, Goa), Northeast India (Meghalaya, Assam), Odisha, and Chhattisgarh. These regions receive heavy rainfall, which causes leaching. Laterite soil is suitable for tea, coffee, cashew, rubber, and coconut cultivation.

✅ Answer: C) Rich in Nitrogen and PhosphorusBlack soil is NOT rich in Nitrogen and Phosphorus — it is actually poor in these nutrients. Black soil is rich in Calcium, Magnesium, Potassium, and Iron. It has high moisture retention, self-ploughing property, and is formed from volcanic lava (Deccan Trap). Nitrogen and Phosphorus fertilisers need to be added for cultivation.

✅ Answer: C) Arid/Desert soilThe Thar Desert of Rajasthan has arid/desert soil. It is sandy, has low moisture content, high salt content, and is poor in humus. It is alkaline in nature. With irrigation, bajra and jowar can be grown. The Indira Gandhi Canal (Rajasthan Canal) has transformed parts of the Thar Desert into agricultural land.

✅ Answer: B) Best soil for cotton due to high moisture retentionBlack soil is called “Cotton Soil” because it is the best soil for cotton cultivation. Its high moisture retention capacity keeps the soil moist for a long time, which is ideal for cotton (a water-intensive crop). Maharashtra is the largest cotton-producing state in India, and most of it is grown in black soil areas.

✅ Answer: B) Preventing soil erosion on slopesContour ploughing is a method of ploughing along the contour lines (horizontal lines of equal elevation) on slopes. This creates ridges that slow down water runoff and prevent soil erosion. Other soil conservation methods include terracing, strip cropping, afforestation, check dams, and crop rotation.

✅ Answer: C) BrickThe word “laterite” is derived from the Latin word “later” meaning brick. This is because laterite soil becomes brick-like when dry — it can be cut into blocks and used as building material. Many ancient temples and buildings in Kerala and Karnataka are built with laterite blocks. When wet, laterite soil is soft and can be easily cut.