KALYANSIR.NET
ü Soil
can be defined as an unconsolidated layer
formed from litho logically varying rocks by weathering agencies which
is then modified by many organic and biochemical processes.
ü The colour of soils depends upon factors such as their age, composition and the
amount of water available to them and utilized by them.
SOIL
GROUPS OF INDIA:
The Indian
Council of Agricultural Research (ICAR) has divided Indian soils into eight
major types.
ü Red
soils
ü Black
soils
ü The
Indo – Gangetic alluvium or alluvial soils
ü The
lateritic and late rite soils
ü Forest
and hill soils
ü Alkaline
and Saline soils.
ü Desert
soils
ü Peaty
and organic soils.
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RED SOILS:
ü Red
Soils are mainly formed due to decomposition of ancient crystalline rocks like
granites and gneisses and from rock types rich in minerals such as iron and
magnesium.
ü The
term ‘red soil’ is due to the wide diffusion of iron oxides through the
materials of the soil.
ü The
Red soils are generally poor in nitrogen, phosphorous, humus.
ü The
Red soils are rich in potash.
ü They
are siliceous or aluminous in character.
ü The
Red soils cover almost the whole of Tamil Nadu, Karnataka, Andhra Pradesh, South
Eastern Maharashtra, eastern parts of Madhya Pradesh, Parts of Orissa,
Jharkhand and Bundelkhand.
ü The
Red soils are most suitable for growing vegetables, rice, ragi and tobacco.
ü Irrigation
is a must for the red soils.
BLACK
COTTON SOILS:
ü These
soils are derived from basalts of Deccan Traps.
ü They
derive their name from black colour.
ü The
black colour is due to the presence of Titanium.
ü Black
soils are fine, grained and highly argillaceous and consist of calcium and
magnesium carbonates.
ü Black
soils contain high quantities of iron, aluminum, lime and magnesia.
ü These
soils generally show poor percentages of phosphorous, nitrogen and organic
matter.
ALLUVIAL
SOILS:
ü These
are essentially transformed soils.
ü They form the most important and largest of all the soil groups.
ü They form the most important and largest of all the soil groups.
ü The
alluvium is of two types.
·
The khadar
·
The bhangar (old
Alluvium)
ü The
khadar is light in colour.
ü The
khadar is more siliceous in composition and composed of newer deposits.
ü The
bhangar or the old alluvium is composed of lime nodules (kankar) and has a
clayey composition.
ü Alluvial
soils are found throughout the plains of northern India.
ü In
the Indian Peninsula, they are confined mainly to the river deltas on the east
coast, the lower valleys of the Narmada and the Tapti, northern Gujarat and
Chhattisgarh plains.
ü The
soils are suitable for the cultivation of cereals, pulses, oilseeds, cotton,
sugarcane and vegetable.
ü Alluvial
soils favor jute cultivation in the eastern parts of the Indian plains.
LATE
RITE AND LATERITIC SOILS:
ü These
soils possess a compact to vesicular mass.
ü These
are mainly composed of hydrated oxides of iron and aluminium.
ü Laterisation
is due to the loss of silica from the soil profile in humid regions where the
process of leaching is widespread.
ü Lateritic
soils are deficient in nitrogen.
ü The
humus is absent except in the late rite soils developed in the forested areas
such as western Karnataka.
FOREST SOILS:
ü The
forest soils are mostly found in forests and mountains.
ü These
soils have a high content of organic matter and nitrogen.
ü Forest
soils are deficient in potash, phosphorus and lime.
ü Tea,
coffee, tropical fruits and spices are obtained from plantations on these soils
especially in South India.
ü In
some states the crops like Wheat, maize, barely are cultivated.
PERCENTAGE OF DIFFERENT SOILS IN THE
TOTAL SOIL COVER OF INDIA
ü Alluvial
soils (riverine alluvium, coastal alluvium, deltaic alluvium, saline and alkali
soils and calcareous alluvial soils) - 23.40 per cent.
ü Sandy
soils (grey brown soils and desert soils) - About 8.46 per cent
ü Black
soils (deep black, medium black and shallow black soils, and mixed red and
black soils) –– 24.12 per cent.
ü Red
soils (red loamy soils, red gravelly sandy soils, and red yellow loamy soils) –
29.08 per cent.
ü Laterite
soils –– 4.30 per cent.
ü Other
soil groups (hill soils, sub - montane or podosolic soils, mountain meadow
soils, terai soils, and skeletal soils) – 10.64 per cent.
CROPS GROWN
Alluvial - Rice, wheat, sugarcane, oilseeds
Black -Cotton, sugarcane, tobacco,
oilseeds
Red -Wheat, rice, cotton, sugarcane, pulses. Desert - Wheat, grams, melon, bajra (with irrigation). Laterite -Coffee, rubber, cashewnut, tapioca. Marshy - Jute. KALYANSIR.NET |