Soil Resources Flashcards
Define Soil
The thin layer of loose mixture of rock particles and rotting organic matter that covers much of the land
What are the constituents of soil?
Decomposed vegetal and animal remain (humus), silica, clay and sand
Define soil fertility
The ability of soil to sustain plant life
How is alluvial soil formed?
Alluvial soil is formed by the deposition of river load as the river flows from upper course to lower course.
Why is alluvial soil known as riverine soil?
Because it is mainly found in river basins
What is bhangar? What is its composition?
Bhangar is older alluvium. It is composed of lime nodules (kanker) and has a clayey composition. It is above the flood levels of rivers.
What is khadar?
Khadar is newer alluvium and is more fertile as newer layers are deposited year after year during monsoon floods. It is composed of fine silt and clay and is lighter in colour.
Where is inland alluvium found?
Plains of the Ganga, Indus, and Brahmaputra
Where is deltaic alluvium found?
In deltas of Ganga-Brahmaputra, Mahanadi, Krishna and Kaveri
Where is coastal alluvium found?
Coastal strips of peninsular India and the plains of Gujarat
What is the texture of alluvial soil in upper reaches of river valleys? In the lower reaches?
Upper Reaches - soil is coarse, large and non-uniform
Lower reaches - smaller particles, more uniform
Which states is alluvial soil found in?
Punjab, Haryana, Assam
How does the alluvial soil of the Upper Ganga Valley differ from that of the Lower Ganga Valley
Upper Ganga Valley - dry, porous, sandy, faint yellow, consisting of clay and organic matter
WB (lower Ganga Valley) - more compact, less coarse and more moist
Why is alluvial soil easily tillable?
It is light and porous
Is alluvial soil fertile? What minerals does it contain? What minerals is it deficient in?
Yes. rich in minerals - (especially) potash and lime
Deficient in nitrogen and humus
What crops is alluvial soil suitable for growing?
Rice, wheat, sugarcane, tobacco
Jute(lower Ganga-Brahmaputra Valley)
Why is Black soil said to be a residual soil?
It is formed at the place of its origin over the underlying rocks.
Why is black soil also known as lava soil?
As it is formed by the denudation of igneous or volcanic rocks
What are the different names for black soil?
Black cotton soil, Regur Soil, Lava Soil
Where is Regur Soil found?
Deccan Lava Tract - Maharashtra, Madhya Pradesh, Gujarat, Karnataka