Assam GK Section

Soil Types of Assam

Compiled on 2026-01-18

Assam's soils are nitrogen-rich yet erosion-prone, shaped by riverine alluvium, piedmont fans, hill slopes and lateritic plateaus.

Key pointers

Alluvial soils dominate the Brahmaputra and Barak plains, support cereals, pulses, oilseeds and plantations, and include younger char-land deposits and older brown loams of upper Assam.
Piedmont soils occupy the Himalayan foothill bhabar and tarai belts with unassorted detritus grading into saturated sandy-silty zones of tall grasses.
Hill soils—red sandy and red loamy—line the Assam-Meghalaya border, Karbi plateau and Barail hills; they are deep, acidic and rich in organics but can lack phosphates and lime.
Lateritic soils blanket North Cachar Hills, southern Karbi Anglong and patches near Golaghat and Barak plains, featuring dark heavy loams deficient in nitrogen, potash and lime.
Soil erosion is severe: 6,116 hectares were recorded as lost in the Upper Brahmaputra and North Bank in 1994, and about 3.2 million hectares of plains are vulnerable to topsoil runoff, while 1.53 million hectares of hill slopes face mass-movement degradation.

Active floodplains of the Brahmaputra and Barak

Sandy to silty loams, slightly acidic near riverbanks, low in phosphoric acid and humus

Best for: Oilseeds, pulses, rabi crops

Belts between piedmont and new alluvium in Kokrajhar, Barpeta, Nalbari, Kamrup, Darrang, Sonitpur, Lakhimpur, Dhemaji and the Kopili plain

Very deep brown to yellow fine-to-coarse loams, slightly to moderately acidic

Best for: Rice, vegetables, perennial plantations

Narrow Himalayan foothill zones from the Assam-Arunachal border to beyond the Subansiri

Bhabar includes boulders, pebbles, sand and silt; tarai zones are sandy to silty loams that remain saturated

Best for: Tall grasses, swamp forestry, groundwater recharge

Karbi Anglong, Barail range, Assam-Meghalaya border and eastern foothills

Red sandy soils are deep, well drained and organic-rich; red loamy soils are coarse, acidic and low in nitrogen, phosphoric acid and lime

Best for: Horticulture, shifting plantations when managed sustainably

North Cachar Hills, southern Karbi plateau, eastern Hamren, southern Golaghat fringe and northern Barak plain

Dark heavy loams deficient in key nutrients

Best for: Forestry and careful agroforestry with soil amendments