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TitleSoil classification
Tags Desert Weathering Organic Matter Erosion
File Size165.7 KB
Total Pages14
Table of Contents
                            FACTORS OF SOIL FORMATION
Interactions of Soil Formation Factors
	Climate
	Plant and animal life
                        
Document Text Contents
Page 1

Soil classification
The sub-discipline of soil science which deals with the systematic categorization of soils based on
distinguishing characteristics developed during soil genesis as well as criteria that dictate choices in
land use and soil management.

It is also true that Pakistan’s soil can be classified regionally, or according to where it is found in the
county. From that perspective, there are also six soil types:
1. Indus basin soils: The soils found along the current course of the Indus River are due to alluvial
deposits made by that river depositing sediments every spring.
2. Bongar Soils: These soils are found in the historic Indus plain and are the best soils for agriculture
in the country. Usually they’re far from the present-day bed of the Indus River.
3. Khaddar Soils: Also found along Pakistan’s rivers is this soil. It formed when, every year during
flood, a new layer of salty clay was deposited.
4. Indus Delta Soils: These soils cover the current Indus River delta. Most of this soil is very clayey
and was developed under seasonal floodwaters.
5. Mountain Soils: These rocky soils mostly cover the highlands of northern and western areas of
Pakistan.
6. Sandy Desert Soils: These soils are made by the deposition of sand, layer by layer, year after year,
for thousands of years. They’re found in the arid and semi-arid areas of Pakistan.

Soil
The upper layer of the earth which is composed of different thin rock particles is helpful in the
growth of vegetation and plants that is called soil.

Basic Components of Soil
Soil has three basic components.
1. Solid particles like salt, mineral and organic matter.
2. Air.
3. Water.
Importance of Soil
The kind of soil totally depends upon climate, location, vegetation and rock material. The agriculture
of a country depends upon her soil’s structure and kinds. Soil is a gift of nature.

Alluvium
Those materials which are transported from one place to another by rivers and deposited at other
places are called alluvium.
Aeolian Soil
Similarly wind also transports the material from one place to another which is deposited over the
surface that is called Aeolian Soil.

Classification of Soils
The soil of Pakistan may be classified according to the regional basis.

Indus basin Soils

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The indus plain is made with the deposition of alluvium by the indus river its tributaries. For the last
thousands of years rivers have been depositing the soil in the form of layers. These soils have more
calcium carbonate and less organic matter. These soils are divided into three main categories.

Bongar Soils
Bongar soils cover a vast area of indus plain. The area includes most of the part of Punjab, Peshawar,
Mardan, Bannu and Kachhi plain. A major part of the province of sindh is also comprised of these
soils. Some of these soils are rich and irrigated give very good production. Usually these soils are far
from the present rivers beds.

Khaddar Soils
Khaddar soils are also formed along the rivers. So every year new layer of salt clay is deposited.
These soils have low content of organic matter and salt.

Indus Delta Soils
These soils cover the river Indus Delta. They extent from Hyderabad to the south coastal area. Most
of the soils is clay and developed under floodwater. Rice is cultivated in the major part of these soils.

Mountain Soils
These soils mostly cover the highlands of northern and western areas of Pakistan. The soils of
northern mountainous areas have high content of organic matters because the climate is moist.
Whereas the soils of western mountainous areas have high content of calcium carbonate and low
content of organic matter because the climate of these areas is arid and semi-arid. The soils of
Pothwar plateau have high lime content. They are productive when plenty of water is available.

Sandy Desert Soils
The soils cover the western areas of Balochistan, Cholistan and the desert of Thar in Pakistan. They
are formed by layers of sand particles. They have moderate quantity of calcium carbonate. They are
made of disposition of sandy soil layer by layer Arid and semi-arid type of climate effect these soils.
So the economic activities are very low in deserts.

From a variety of sources:
About 60% of Pakistan's total land area is classified as unusable for forestry or agriculture because it
consists of deserts and mountains. Pakistan’s soils are mostly dry and have high concentrations of
calcium carbonate and a low content of organic matter. The major soil groupings are Indus basin
soils, mountain soils, and sandy desert soils.

74.3% of Pakistan’s soils are composed of these six types of soil:
1. 30.6% Mountain/Valley: Patchy soils that are a loamy-gravelly mix
2. 14.7% Rolling/hilly sandy soils
3. 11.4% Loamy-clayey soils
4. 6.6% Rock out-crop and loamy soils, very shallow
5. 5.8% Mainly loamy to partly gravelly soils

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Pakistan’s continental type of climate is characterized by extreme variations of temperature, both

seasonally and daily. High elevations modify the climate in the cold, snow-covered northern

mountains; temperatures on the Balochistan plateau are somewhat higher. Along the coastal strip, the

climate is modified by sea breezes. In the rest of the country, temperatures reach great extremes in the

summer; themean temperature during June is 100 °F (38 °C) in the plains, where the highest

temperatures can exceed 117 °F (47 °C). Jacobabad, in Sind, has recorded the highest temperature in

Pakistan, 127 °F (53 °C). In the summer, hot winds called loos blow across the plains during the day.

Trees shed their leaves to avoid excessive moisture loss. The dry, hot weather is broken occasionally

by dust storms and thunderstorms that temporarily lower the temperature. Evenings are cool; the

diurnal variation in temperature may be as much as 20 to 30 °F (11 to 17 °C). Winters are cold, with

minimum mean temperatures of about 40 °F (4 °C) in January.

Plant and animal life

Differences of latitude, elevation, soil type, and climate have favoured a variety ofplant growth.

Drought-resistant vegetation in the desert consists of stunted thorny scrub, mostly acacia. The plains

present a parkland view of scattered trees. Dry scrub forests, called rakhs, grow in parts of the arid

plain. In the northern and northwestern foothills and plains, shrub forests, principally acacia, and wild

olive are found. In the wetter parts of the northern and northwestern mountains, evergreen coniferous

softwood forests, with some broad-leaved species, grow. Fir, deodar, blue pine (Pinus wallichiana),

and spruce are the principal coniferous trees. At lower elevations, below 3,000 feet (900 metres),

broad-leaved oaks, maples, birches, walnuts, and chestnuts predominate. Conifers are an important

source of commercial timber. In the arid landscape of the Potwar Plateau, some hills are only thinly

wooded. In the northern ranges of the Balochistan plateau are some groves of pine and olive.

The babul tree(Acacia arabica) is common in the Indus River valley, as are many species of fruit

trees. The country’s forest cover is naturally sparse, but it has been diminished further by excessive

timber cutting and overgrazing.

Destruction of natural habitats and excessive hunting have led to a reduction in the range of animal

life in large parts of the country, but wildlife can still be found in abundance in some areas. The

variety of large mammals in the northern mountains includes brown bears,Asiatic black

bears (Ursus thibetanus, also known as the Himalayan bear), leopards, rare snow leopards, Siberian

ibex (Capra ibex sibirica), and wild sheep, including markhors, Marco Polo sheep (Ovis

ammon polii, a type of argali), and Chiltan wild goats (Capra aegagrus chialtanensis).

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Page 14

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