Consider the following statements regarding soils: 1. Soils having a very high content of sodium and calcium and pH of more than 7.0 are alkaline soils. 2. Black cotton soil had developed on the Deccan basaltic lava under hot and humid conditions. 3. Laterite soils are characterised by a deep weathered layer from which silica has been leached. Which of the statements given above is/are correct?

Soils with high sodium and calcium and pH above 7.0 are alkaline (saline-alkaline) soils, so Statement 1 is correct. Black cotton (Regur) soil developed on Deccan basaltic lava is typically described in NCERT as forming under hot and humid (alternating wet and dry) climatic conditions, so Statement 2 is accepted as correct. Laterite soils form under hot, humid tropical climates with alternating wet and dry seasons, leading to a deep weathered profile from which silica has been leached, leaving behind iron and aluminium oxides, so Statement 3 is correct. All three statements are correct.