Why is khadar more fertile than bhangar?

Khadar is more fertile than bhangar because khadar consists of newly deposited alluvial soil that is regularly renewed by river floods with nutrient-rich silt and sediments. This constant replenishment makes khadar soil finer, more moisture-retentive, and highly suitable for agriculture. In contrast, bhangar is older alluvial soil found higher above flood levels; it is not renewed annually, is coarser, often contains calcareous nodules (kankar), and thus is generally less fertile than khadar.