Kankar
Also called: Kanker · Topic: Soils of India: Types, Degradation and Conservation · NCERT: Class 11, Ch 5 "Geomorphic Processes"
Meaning
Kankar means small, hard lumps (nodules) of calcium carbonate (lime) found in the soil. Kankar forms in areas of moderate rainfall. Water dissolves lime in the upper soil and carries it down. When the water evaporates or stops moving, the lime is left behind and hardens into lumps. Thick kankar layers make soil less fertile and stop water from soaking down.
Example
The bhangar (old alluvium) on the higher terraces of the Ganga plain in Uttar Pradesh is full of kankar. In the arid soils of western Rajasthan, kankar fills the lower layers, because calcium increases with depth there. This kankar layer blocks water from soaking in.
Don't confuse with
- Khadar: khadar is the new, fine-grained floodplain alluvium. Floods renew it every year, so it has little kankar and is more fertile than bhangar.
- Laterite: laterite hardens because iron and aluminium oxides are left in it. Kankar is calcium carbonate.