Geography [1 Mark Question Answer]

Alluvial Soils occupy the extensive tracts of Punjab, Uttar Pradesh, Bihar, Bengal, Orissa, and the coastal strips of Peninsular India. They also occupy parts of Gujrat and Rajasthan.

Humus: The decaying of organic materials, e.g., dead leaves, stems, roots, living bacteria, fungi, worms etc., produce humus, which is important for Soil fertility.

Fertilizers and mixed farming.

‘In situ’ are the Soils which are found where they are formed.

Alluvial Soil and Black Soil are the most important Soils.

The conditions of climate, topography, vegetation and underlying rock can alter the characteristics of Soil.

Sometimes in dry areas, dust and silt may be lifted and carried to a great distance by the wind. This is known as Wind erosion.

‘Soil’ means the uppermost layer of the earth’s crust, which contains the organic as well as mineral matter necessary for the growth of plants.

When rain falls heavily, the run off scours out deep grooves. This cutting up of the Soil gives rise to bad lands or ravine lands. This type of erosion is known as Gully erosion.

Types of Soil erosion are as follows:
(i) Erosion by water (ii) Erosion by wind.

Soil erosion is prominent in the North-eastern hilly region of Arunachal Pradesh, Assam, the Chambal Valley, West Bengal and Thar Desert.

The Soil affected by Soil erosion is Laterite Soil. The important crops of this Soil is Tapioca and Cashewnuts.

Name two states where this type of soil is found.
(i) Laterite soil (ii) Orissa and Karnataka.

Red Soil is formed due to the prolonged weathering of the old crystalline rocks. They have a mixture of clay and sand.

The crop that thrives best in Regur Soil is Cotton. It is exported from Mumbai sea-port. The crop that thrives best in Red Soil is Sugarcane. It is exported from Chennai.

Cotton, Sugarcane, Groundnut, Jowar and Bajra.

Iron, Calcium, Aluminium and Magnesium.

Sometimes it has high content of sodium salts which makes it unproductive.

Black cotton Soil; Cotton and Sugarcane.

Pedology is the subject deals with the study of soil.

Black Soil is also known as ‘Regur Soil’ or ‘Black Cotton Soil’. Black Soil is found in Gujrat, Maharashtra, parts of Madhya Pradesh, South Uttar Pradesh, North-west Orissa and the western parts of Andhra Pradesh.

Black Soil is formed as a result of denudation of lava-flow rocks. They contain large quantities of lime, potash, aluminium, magnesium. They are deficient in phosphorus, nitrogen and organic matter. Black Soil is highly retentive of moisture, and become sticky when wet.

It is Black in colour therefore it is called Black Soil. These Soils are also called Regur Soil. These are formed in situ, i.e., formed where they are found. These Soils have originated from solidification of basic lava spread over large areas of Deccan Plateau during volcanic activity.

The Alluvial Soil of the Ganga plain is formed due to the deposition of alluvium which is brought from the Himalayan region. These are light in colour. The Alluvial Soil of the Godavari valley is formed due to the deposition of alluvium brought mainly from the Deccan trap region which is volcanic in origin. It is dark in colour.

The chief region of Alluvial Soils in India is the Indo-Gangetic plain, where Alluvial Soils have been deposited mostly by rivers. The coastal belts are the areas of alluvium. The deltaic alluvium on the eastern coast has also been deposited by river-channels. Therefore, Alluvial Soils are rightly called Riverine Soils.

Soil conservation refers to the methods of protecting the soil from erosion. Roots of the trees protect the soil by holding it in place against wind and water erosion. Re-afforestation means replanting trees which have been cut down. For every tree that is cut, two trees are grown. In this way forest cover is increased.

(i) Terrace farming.
(ii) Planting shelter belts to check the speed of wind.

Sandy and porous Soils are subjected to least erosion by water action because they absorb a good amount of water at the time of rainfall. Impervious Soils are subjected to gradual erosion by water because they are incapable of absorbing rainwater.

Some measures to check Soil erosion are: Contour method of ploughing, terraced farming, plugging of gullies and ravine method, constructing dams across the streams, check on unrestricted grazing over the pastures, afforestation and legal binding on primitive method of Jhooming cultivation should be exercised.

When wind blows over barren land, there will be damage to the top Soil. In the areas of scanty rainfall wind erosion is predominant. When deaf-forestation due to over-grazing of cultivation makes the top Soil bare, wind erosion occurs.

Slip erosion is caused by hydraulic pressure exerted by moisture penetrating into the Soil
during heavy, raips. Sometimes the entire field on hill side may slide down because of slip erosion.

The tidal waters of sea cause considerable Soil erosion along the coast, particularly during the rainy season when the sea gets rough. The roaring waves rush and dash on the coast, swallowing every time bits of coastal lands.

The banks of the streams or rivers get eroded every year by the flowing water. In certain areas, the streams and rivers often change their course bit by bit every year and their beds get widened.

In rill erosion small finger-like rills begin to appear on the landscape. These rills are usually smoothened out by working of the farm implements. But, slowly the rills increase not only in number but also in their shape and size. They get wider and deeper. This reduces the actual area under crop and results in declining crop yields.

When the vegetation cover of an area is removed, the rain water instead of sinking into the ground, washes the Soil down the slope. Each succeeding rain-stream washes away a thin layer of absorbent top Soii. This is known as Sheet Erosion.

Soil is the thin layer of loose mixture of small rock particles and rotting organic matter that covers much of the world’s land surface. It supports all forests, grasslands and crops from which all living creatures on earth derive their food.

The washing away or the removal of the Soil is known as Soil erosion. Soil erosion, thus, may be termed as the detachment and transportation of Soil particles by agents of denudation such as weathering, running water and wind, etc.

Laterite Soils are found on the summits of the Eastern Ghats. These are formed in the areas
which experience high temperature and heavy rainfall. They are formed by the process of leaching.

Laterites are intensively leached Soils of the monsoon climate. They lack in elements of fertility and thus are normally of low value for crop production. Laterite Soil is found in India in hill summits ot Eastern and Western Ghats and Assam Hills.

It is found m Andhra Pradesh, Tamil Nadu, Karnataka, Assam, Bengal, Orissa and along the Western and Eastern Ghats.

It is formed by the weathering of Soil or due to intense leaching during the periods of heavy rainfall. All the soluble materials are removed and a hard stony layer remains.

The Red Soils are generally poor in nitrogen, phosphoric acid and humus. They become reasonably fertile when fertilizers are added to it.

Red Soil is found in Tamil Nadu, Karnataka, South-eastern Maharashtra, parts of Andhra Pradesh and Orissa. They are also found in the southern districts of Uttar Pradesh, Madhya Pradesh and eastern Rajasthan.

It retains moisture for a long time, is rich in lime, potash and calcium.

Black Soil is formed by weathering of volcanic rocks. It is found in Maharashtra and M.P.

Soil is formed by the Parent rock material through a process of break up or wear and tear. The decomposition of plant remains, animal manures and dead animals add to the fertility of the soil.

The parent rock of Laterite Soil is Laterite rock. It is mainly found in the Malwa Plateau region.

It is found along summits of Western Ghats in Karnataka and Kerala.

Laterite Soil; Kerala and Karnataka.

Red soil is suitable for the cultivation of wheat, rice, millet, gram, pulses and sugarcane.