Describe alluvial and black soil in India on the basis of area of distribution, formation, composition and sustainability of crops
Answers
Answer: alluvial soil
fromation Alluvial soils are formed mainly due to silt deposited by Indo-Gangetic-Brahmaputra rivers. In coastal regions some alluvial deposits are formed due to wave action.
charecteristics
They are immature and have weak profiles due to their recent origin.
Most of the soil is Sandy and clayey soils are not uncommon.
Pebbly and gravelly soils are rare. Kankar (calcareous concretions) beds are present in some regions along the river terraces.
The soil is porous because of its loamy (equal proportion of sand and clay) nature.
Porosity and texture provide good drainage and other conditions favorable for agriculture.
These soils are constantly replenished by the recurrent floods.
distribution they occur all along the Indo-Gangetic-Brahmaputra plains except in few places where the top layer is covered by desert sand. They also occur in deltas of the Mahanadi, the Godavari, the Krishna and the Cauvery, where they are called deltaic alluvium (coastal alluvium) Some alluvial soils are found in the Narmada, Tapi valleys and Northern parts of Gujarat.
example cotton sugarcane
black soil
charecteristics
A typical black soil is highly argillaceous [Geology (of rocks or sediment) consisting of or containing clay] with a large clay factor, 62 per cent or more.
In general, black soils of uplands are of low fertility while those in the valleys are very fertile.
The black soil is highly retentive of moisture. It swells greatly on accumulating moisture. Strenuous effort is required to work on such soil in rainy season as it gets very sticky.
In summer, the moisture evaporates, the soil shrinks and is seamed with broad and deep cracks. The lower layers can still retain moisture. The cracks permits oxygenation of the soil to sufficient depths and the soil has extraordinary fertility.
distribution
Spread over 46 lakh sq km (16.6 per cent of the total area) across Maharashtra, Madhya Pradesh, parts of Karnataka, Telangana, Andhra Pradesh, Gujarat and Tamil Nadu.
formation
The parent material for most of the black soil are the volcanic rocks that were formed in the Deccan Plateau (Deccan and the Rajmahal trap)
example rice
Alluvial soils are formed mainly due to silt deposited by Indo-Gangetic-Brahmaputra rivers. In coastal regions some alluvial deposits are formed due to wave action.
*They are immature and have weak profiles due to their recent origin.
*Most of the soil is Sandy and clayey soils are not uncommon.: