Which of the following soil types, locally known as 'regur' or black cotton soil, covers extensive areas of the northern districts of Tamil Nadu and the Deccan trap region, and is renowned for its high moisture retention capacity?

💡 Solution & Explanation

Black soils, commonly referred to as regur, are formed from the weathering of underlying basaltic lava rocks and are rich in clay minerals like montmorillonite, giving them high water-holding capacity and self-churning properties. Red soils are predominant across most of central and southern Tamil Nadu, formed from the weathering of ancient crystalline rocks. Laterite soils develop in regions of high temperature and alternating wet and dry spells. Alluvial soils are deposited along major river floodplains and deltas.