India’s “Regur” or Black Cotton Soil is a direct geographical legacy of ancient volcanic activity. It formed from the mechanical and chemical weathering of basaltic lava deposited during the Deccan Trap eruptions at the end of the Cretaceous period. This soil is rich in lime, iron and magnesium but poor in phosphorus and nitrogen. Its most unique geographical property is its “self-ploughing” nature—it develops deep cracks during the dry season, allowing for aeration and becomes sticky when wet. This fertile soil is the backbone of agriculture in the Deccan region, particularly for moisture-dependent crops like cotton and sugarcane.