2. WHAT IS SOIL
Soil is the layer of broken rock particles and
decaying organic matter on the surface of earth,
which is essential for the growth of plants.
Mineral and organic material that supports
plant growth on the earth’s surface.
Mixture of particles of rock , organic materials ,
living forms , air and water.
3.
4. TYPES OF SOIL
Alluvial soil
Black soil
Red soil
Clay soil
Mountain soil
Desert soil
Saline and Alkaline soil
Peaty and Marshy soil
Residual soil
Marine soil
6. ALLUVIAL SOIL
Alluvial soil is formed when a soil carrying
stream gradually loses it carrying capacity with
decreasing velocity.
In slowing down, a river does not have
sufficient power to keep the large particles of
soil suspended ; these particles settle to the
riverbed.
Further decrease in velocity causes smaller
particles to settle.
These particles are deposited, finally, at the
mouth of the river ,where they form DELTAS of
fine-grained soil.
7.
8. BLACK SOIL
Black soil also known as regur or black cotton soil.
Dark grey to black in color . High clay content .
Highly moist retentive.
Develops cracks in summer . Covers 5.4 lakh
sq.km. highly suitable for cotton.
Rich in iron , lime , calcium ,magnesium
,carbonates ,and alumina.
9.
10. RED SOIL
Red soil formed due to weathering of old crystslline
rocks.
More sandy and less clayey. Rich in iron, small
amount of humus.
Poor in phosphorus, nitrogen and lime.
Slightly acidic and do not retain moisture. 3.5 lakh
sq.km area. Porous and friable.
11.
12. CLAY SOIL
Clayey soil is made of a relatively higher proportion
of fine particles
Unlike sandy soils, these soils have very less space
between particles
Because the particles are smaller in size, water can
be trapped in the tiny gaps between them
Clay soils are heavy and hold more water.
13.
14. MOUNTAIN SOIL
Mountain soil found in hill slops.
Formed by deposition of organic matter from forest
Rich in humus . poor in potash and lime.
15.
16. DESERT SOIL
Desert soil contains soluble salts . Originated by
mechanical disintegration and wind deposit.
Porous and coarse . 90% sand and 5% clay . Rich
in nitrates and phosphates.
Poor in nitrogen & humus . Friable, sandy and low
moist content .1.4 lakh sqkm.
17.
18. SALINE & ALKALINE SOIL
Saline & alkaline soil contains salts like sodium,
magnesium , calcium.
Infertile ,unfit for cultivation. Sandy to loamy in
texture.
19.
20. PEATY AND MARSHY SOIL
Peaty and marshy soil occur in humid region.
Formed by accumulation of organic matter. Black in
colour. Highly acidic and heavy.
Though the soil is rich in organic matter, nutrients
present are fewer in this soil type than any other
type
Peaty soil is prone to water logging but if the soil is
fertilized well and the drainage of the soil is looked
after ,it can be the ideal for growing plants
21.
22. RESIDUAL SOIL
Residual soil are those that remain at the place of
their formation as result of the weathering of the
parent rock.
The depth of residual soil depends primarily on
climate conditions and the time of espouser.
In temperate zones residual soils are commonly
stiff and stable.
An important characteristics of residual soil is that
the sizes of grains are indefinite.
23.
24. MARINE SOIL
Marine soil is formed from material carried into the
seas by streams and by material eroded from the
beaches by the tidal action of the waves.
Part of the material is carried out and deposited in
deep water ; part is heaped upon the beaches
along the coast.
25.
26. GLACIAL SOIL
Glaciers carry with them soils varying in size from
fine grained to huge boulder.
Soil get mixed with the ice and are transported far
away from their original position.
Drift is a general term used for the deposits made
by glaciers.
27.
28. COHESIVE SOIL
A sticky soil, such as clay or silt; its shear strength
equals about half its unconfined compressive
strength.
Soil in which the absorbed water and partical
attraction act such that it deforms plastically at
different water contents are known as cohesive
soils or clays.
These soils possess higher plasticity eg: clays and
plastic silt.
29.
30. LOAMY SOIL
Loamy soil is a mixture of sand, soil and silt.
Slit particles are present between sand and soil
particles.
It also contains humus, and is, therefore , consider
the best for the growth of plants.
The percolation rate is between that of sandy soil
and clay soil.
31.
32. LATERITE SOIL
Laterite soil latin word meaning brick. Formed
under high temperature and rainfall with wet and
dry spell.
Silica is leached due to high rainfall. Remnants of
iron and aluminum oxides left behind is know as
laterite.
Brown to yellowish color. Becomes hard when
exposed to atmosphere. Used as building material.
35. AEOLIAN SOIL
Aeolian soil sedimentary processes are those
involving transport and deposition of material by the
wind.
The whole of the surface of the globe is affected by
the wind to varying degrees, but aeolian deposits
are only dominant in a relatively restricted range of
settings.