Red and Yellow Soil of India

Red soil and yellow soil aren’t two different soils. They’re the same soil, coloured differently by how much water reached the same iron mineral.

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Indian Geography · IndGeo0015

Red and Yellow Soil: One Rock, Two Colours

Red Soil

Iron oxide stays fully oxidised — the classic red colour of the Deccan’s eastern fringe.

Yellow Soil

The same iron oxide, but hydrated by extra moisture, turns the soil yellow instead.

Shared origin

Both form from the long weathering of ancient crystalline and metamorphic rock — mainly granite and gneiss — across Tamil Nadu, Karnataka, Andhra Pradesh, Telangana, Odisha, and Chhattisgarh.

Fertile enough, with help

Low in nitrogen, phosphorus, and humus on its own — but with irrigation and fertiliser, it still supports millets, pulses, groundnut, cotton, and tobacco.

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Must Know

• Red and yellow soil forms from the long weathering of ancient crystalline and metamorphic rock, mainly granite and gneiss.
• Iron in the parent rock reacts with oxygen. That reaction gives the soil its colour.
• Where the iron oxide stays fully oxidised, the soil turns red.
• Where the same iron oxide becomes hydrated, in moister conditions, the soil turns yellow instead.
• It covers a large stretch of the Deccan Plateau’s eastern edge and the wider peninsular region.

Good to Know

• Red and yellow soil dominates in Tamil Nadu, Karnataka, Andhra Pradesh, and Telangana.
• It also appears in Odisha, Chhattisgarh, the southern middle Ganga plain, and along the Western Ghats’ piedmont zone.
• Compared to alluvial soil, it runs low in nitrogen, phosphorus, and humus.
• It’s generally light-textured, and less fertile on its own, without added inputs.
• With irrigation and fertiliser, it still supports millets, pulses, groundnut, cotton, and tobacco.

Test Yourself

Please wait…

1. Red and yellow soil forms mainly from the weathering of which type of rock?

Crystalline and metamorphic rock, such as granite and gneiss

Volcanic basalt

River-deposited alluvium

Coral limestone

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Great to Know

• Fine-grained red and yellow soils tend to be more fertile than the coarse-grained versions found on uplands and slopes.
• Red and yellow are two faces of one process: the same iron mineral, just at a different oxidation and hydration state.
• Unlike black soil’s volcanic Deccan Trap origin, red and yellow soil forms from much older granite and gneiss basement rock.
• Because it forms from weathered rock rather than river deposition, it sits closer to hilly, undulating terrain than alluvial soil’s flat plains.