SOILS
Soils
World Soil Day - Dec 5.
World Earth Day - April 22.
Study of Soil is called as Pedology.
The process of soil formation is called as Pedogenesis.
The Science which deals with formation of the soils is called Lithology.
Soil survey of India is established in the year 1956 to carry out of scientific surveys of soils.
Soil Erosion
Soil Erosion is the degradation of the soil into another form
Types of Soil Erosion
There are different types of Soil erosion namely.
1. Leaching:
Due to heavy rainfall the minerals are deposited into the lower layers of the earth.
The upper layer have the soil without minerals.
2. Sheet Erosion
When leaching was continuously occurring the upper layers of the earth eroded sheet wise is called
sheet Erosion.
3. Rill Erosion
When sheet erosion continuously occurring the finger shaped images appears on the upper layers on the earth
is called “Rill Erosion”.
4. Gully Erosion
When Rill erosion is more widened it is called as Gully Erosion.
5. Ravine Erosion
Due to the Gully erosion narrow and shallow holes are occurred on the upper layers of the earth is called as
Ravine Erosion.
In Punjab it is also called as Chaos.
Other name of Ravines are Kandara lands.
Causes of Soil Erosion:
Deforestation
Cattle grazing in the fields
Unscientific farming practices
Substitution farming
Excessive use of chemical fertilizers and pesticides.
Podo agricultural practices
Soil Erosion - Preventive measures:
Taking up social forestry in barren areas.
A check dam constructed across the drainage is called gully plugging.
The field should be ploughed following the contours across the slope of the land. This is called contour
ploughing.
Trenches should be dug along the boundary ridges of the field.
Construction of check dams should be undertaken across the streams.
Watershed schemes should be developed in rainfed areas.
Weed farming should be controlled and terrace farming should be followed.
Crop rotation should be followed.
Contour Bonding procedure should be adopted. That is, the embankment should be built according to the
contours of the terrain.
Step farming should be undertaken in hilly areas.
Depending on the formation, they can be divided into 2 types.
1. Emplacement Soils: Soils formed as a result of deposition of sediment on the parent rock.
Eg: Black soils, Red soils, Laterite soils.
2. Deposited Soils: Alluvial debris transported due to extrusive forces and deposited in another area is called
deposited soils.
Eg: Alluvial soils
Indian Council of Agricultural Research (ICAR) has categorized Indian soils into eight groups namely:
1. Red soils 2. Alluvial soils
3. Black soils 4. Laterite soils
5. Arid and Desert soils 6. Saline and Alkaline soils
7. Mountainous or Forest soils 8. Peaty and Marshy soils
1. Red soils
Red soils are rich in Iron oxide (Fe2O3)
Red soils are formed by the disintegration of Metamorphic rocks caused by a heavy rainfall.
These soils are porous and coarse.
Soil retaining capacity is very less.
Less fertile.
These soils require frequent irrigation.
It is suitable for deep root cultivation crops.
These soils are suitable for, groundnut, pulses, millet.
These soils mostly can be found in Tamil Nadu and Andhra Pradesh.
2. Alluvial soils
These soils are deposited in plains by the river streams.
These soils constitute 40 percent of Indian soils.
These soils are spread across Indo-Gangetic plains, Brahmaputra plains, Coastal plains.
3. Black soils
Black soils are formed by the lava eruption.
The Black soil are formed by the Basalt rock.
It is also called as black cotton soil.
These soils appear black due to the presence of Titaniferous Magnetite.
Black soils mostly spread in Maharashtra, Black soils are called as Regur Soils.
These soils have high water retaining capacity hence suitable for dry crops like Cotton, Sunflower.
These soils are not suitable for heavy irrigation.
These soils are rich in Iron, Aluminum, and Potash.
So black soil is called as a self-ploughing soil.
4. Laterite soils
Laterite is a Latin word it means Brick
These soils can be found in areas that experience a heavy rainfall of more than 200 cm.
In India, these soils can be found in Western ghats, Assam hills, Raj mahal hills, and. Hills of Deccan
plateau.
The soil appears red colour because of Iron
These soils are formed due to leaching of lime and silica from the soil.
These soils are suitable for plantation crops like Cashew, Coffee, Coconut.
These soils are less fertile. So, they need fertilizers.
5. Arid and Desert soils
These soils are spread across dry areas of Rajasthan.
These soils are suitable for millets cultivation.
Jowar and Bajra are the major crops that are cultivated in these soils.
6. Saline and Alkaline Soils
These soils can be found in arid and semi-arid areas of Rajasthan, Punjab, Maharashtra, Uttar
Pradesh.
These soils are infertile and not suitable for agriculture.
These soils have less water holding capacity.
7. Mountainous or Forest soils
These soils can be found in Himalayas, Nilgiris, Vindhyas, Saputras, and other mountain regions
of India.
These soils contain pebbles and kantars.
These soils are acidic in nature due to humus.
These soils are suitable for cultivation of Tropical fruits, Coffee, Tea, Spices.
8. Peaty and Marshy Soils
These soils can be found in coastal states like Tamil Nadu, Odisha, Kerala.
These soils are formed when accumulation of organic matter happens in the water logged areas.
Important Soil research in India
1) Central Forest Soils Research Institute – Ooty
2) Shivalik Soils Research Institute - Chandigarh
3) Himalayan Soils Research Institute – Dehradun
4) Research area of black sand soils - Bellari
5) Desert Soils Research Area – Jodhpur
6) Rajasthan Waste Research Area - Kota
7) Waste research area of Gujarat – Pasad
8) Yamuna Wastewater Research Area – Agra
Percentage of soils in India
1) Alluvial soils are more than 43 %. 2) Red soils - 18.49%
3) Black soils - 15.90% 4) Mountainous soils - 5.50%
5) Desert soils - 4.42% 6) Laterite soils - 3.70%
Note:
To control soil erosion in India, the government of India formed a Central Soil Conservation Board in the year 1953
The main role of the Central Soil Conservation Board is to implement soil conservation programs across India.
