Soils Flashcards
The major factors affecting them formation of soil are
relief, parent material, climate, vegetation and other life-forms and time.
Horizon A’ is the topmost
zone,
where organic materials have got
incorporated with the mineral matter,
nutrients and water, which are necessary for
the growth of plants
Horixon B has some
organic matter in it, although the mineral matter is noticeably weathered.
‘Horizon C’ is composed
of the loose parent material
This layer is the first stage in
the soil formation process and
‘Horizon C’
fertile soil is called
Urvara
Sterile soil is called
Usara
Soil Survey of India, established in , made
comprehensive studies of soils in selected areas
like in the Damodar Valley
1956
The NationalBureau of Soil Survey and the Land Use
Planning an Institute under the control of
the
Indian Council of Agricultural Research (ICAR)
Region of Alluvial soi
northern plains, and river valleys
Nature of Alluvial soil
Sandy loam to clay
Alluvial soil is rich in
potash
Alluvial soil is poor in
Phosphorous
Khadar and bhangar are types of
Alluvial soil
The colour of the alluvial soils varies from
the
light grey to ash grey
Black soil covers m
ost of the Deccan Plateau which includes parts of Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh and some parts of Tamil Nadu
Nature of black soil
clayey, deep and impermeable.
character of black soil soil
low absorption and loss of moisture
self ploughing soil
black soil
the black soils are rich in . Th
lime, iron, magnesia and alumina, potash
the black soils lack in
phosphorous, nitrogen and organic matter
Red soil develops on
crystalline igneous rocks
in areas of low rainfall in the eastern and
southern part of the Deccan Plateau
Along the piedmont zone of the Western Ghat, long stretch of area is occupied by
red loamy soil
Yellow and red soils are also found in parts ofn
Odisha and
Chattisgarh and in the southern parts of the
middle Ganga plai
red soil develops a reddish colour due to a wide diffusion of
iron in crystalline and metamorphic rocks.
Red soil becomes yellow due to
Hydration
Red and yellow soils are generally poor in
nitrogen, phosphorous and humus.
develop in areas with high temperature and
high rainfall. These are the result of intense
leaching due to tropical rains
The laterite soils
soils rich in iron oxide and aluminium compound
The laterite soils
Laterite soils are poor in
organic matter, nitrogen, phosphate and calcium,
laterite soils are rich in
iron oxide and potash are in excess.
are not suitable for cultivation;
however, application of manures and fertilisers
are required for making the soils fertile for
cultivation.
The laterite soils
Red laterite soils in
Tamil Nadu, Andhra Pradesh and Kerala
are widely cut as bricks for
use in house construction
The laterite soils
developed in the higher areas of the Peninsular plateau
The laterite soils
nature of arid soil
red to brown in colour.
They are generally sandy in structure and
saline in nature. I
arid soil is poor in
moisture humus nitrogen organic matter
They are also known as Usara soils.
Saline soils
saline soil rich in
sodium, potassium and magnesium
nature saline soil
sandy to loamy
saline soil are poor in
nitrogen and calcium
peaty soil found in
They are found in the areas of heavy rainfall
and high humidity
peaty soil rich in
humus and organic matter
peaty soil occur in
northern part of Bihar, southern
part of Uttaranchal and the coastal areas of West
Bengal, Orissa and Tamil Nadu
Nature of forest soil
They are loamy and silty on
valley sides and coarse-grained in the upper
slopes. Soil in lower valley is fertile
is called a badland topography
A region with a large number of deep gullies or
ravines
Finger gullies can be eliminated by
terracing.
ICAR has classified the soils of India into the
following order as per the USDA soil taxonomy
Inceptisols 39.74
(ii) Entisols 28.08
(iii) Alfisols 13.55
(iv) Vertisols 0 8.52
(v) Aridisols 4.28
(vi) Ultisols 2.51
(vi) Mollisols 0.4
