Recently,
Indian Council of Agricultural Research has divide
the soil of India into how many types. Alorme them a write
about one type of soil in detail
Answers
Answer:
Have you ever thought about the most
important factor which supports trees,
grasses, crops and numerous lifeforms over the earth’s surface? Can one grow
a blade of grass without soil? While some
plants and organisms which are aquatic in
nature can sustain in water, do they not derive
nutrients from soil through water? You will
realise that soil is the most important layer of
the earth’s crust. It is a valuable resource. The
bulk of our food and much of our clothing is
derived from land-based crops that grow in the
soil. The soil on which we depend so much for
our day-to-day needs has evolved over
thousands of years. The various agents of
weathering and gradation have acted upon the
parent rock material to produce a thin layer of
soil.
Soil is the mixture of rock debris and
organic materials which develop on the earth’s
surface. The major factors affecting the
formation of soil are relief, parent material,
climate, vegetation and other life-forms and
time. Besides these, human activities also
influence it to a large extent. Components of
the soil are mineral particles, humus, water and
air. The actual amount of each of these depend
upon the type of soil. Some soils are deficient
in one or more of these, while there are some
others that have varied combinations.
Have you ever dug a pit in the field of your
school to plant a tree while celebrating VanMahotsava? Was the pit of uniform layer of soil
or did you notice different colours from the top
to the bottom of the pit?
If we dig a pit on land and look at the soil,
we find that it consists of three layers which
are called horizons. ‘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. ‘Horizon B’ is a transition
zone between the ‘horizon A’ and ‘horizon C’,
and contains matter derived from below as well
as from above. It 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 eventually forms
the above two layers. This arrangement of layers
is known as the soil profile. Underneath these
three horizons is the rock which is also known
as the parent rock or the bedrock. Soil, which
is a complex and varied entity has always
drawn the attention of the scientists. In order
to understand its importance, it is essential to
attempt a scientific study of the soil.
Classification of the soil is an effort to achieve
this objective.
CLASSIFICATION OF SOILS
India has varied relief features, landforms,
climatic realms and vegetation types. These
have contributed in the development of various
types of soils in India.
In ancient times, soils used to be classified
into two main groups – Urvara and Usara,
which were fertile and sterile, respectively. In
the 16th centrury A.D., soils were classified on
the basis of their inherent characteristics and
external features such as texture, colour, slope
of land and moisture content in the soil. Based
on texture, main soil types were identified as
SOILS
CHAPTER
SOILS 69
sandy, clayey, silty and loam, etc. On the basis
of colour, they were red, yellow, black, etc.
Since Independence, scientific surveys of
soils have been conducted by various agencies.
Soil Survey of India, established in 1956, made
comprehensive studies of soils in selected areas
like in the Damodar Valley. The National
Bureau of Soil Survey and the Land Use
Planning an Institute under the control of the
Indian Council of Agricultural Research (ICAR)
did a lot of studies on Indian soils. In their effort
to study soil and to make it comparable at the
international level, the ICAR has classified the
Indian soils on the basis of their nature and
character as per the United States Department
of Agriculture (USDA) Soil Taxonomy.
ICAR has classified the soils of India into the
following order as per the USDA soil taxonomy
Sl. Order Area Percentage
No. (in Thousand
Hectares)
(i) Inceptisols 130372.90 39.74
(ii) Entisols 92131.71 28.08
(iii) Alfisols 44448.68 13.55
(iv) Vertisols 27960.00 8.52
(v) Aridisols 14069.00 4.28
(vi) Ultisols 8250.00 2.51
(vi) Mollisols 1320.00 0.40
(viii) Others 9503.10 2.92
Total 100
Source : Soils of India, National Bureau of Soil
Survey and Land Use Planning, Publication
Number 94
On the basis of genesis, colour,
composition and location, the soils of India
have been classified into:
(i) Alluvial soils
(ii) Black soils
(iii) Red and Yellow soils
(iv) Laterite soils
(v) Arid soils
(vi) Saline soils
(vii) Peaty soils
(viii) Forest soils.
Alluvial Soils
Alluvial soils are widespread in the northern
plains and the river valleys. These soils cover
about 40 per cent of the total area of
Explanation: