Soils India: Classification and Characteristics
Soils India: Classification and Characteristics
Soil definition – soil is an upper layer of Earth which has been derived from the rocks and organic matter through agencies of decay and disintegration .
- agents of weathering and erosion break the mountains and rocks into small pieces and convert them in small and fine grains.
- decayed plants and animals elements are also added in the soil which is known as humus .
- the soil formation is a very slow process and has taken thousands of years to form .
- Various agents of weathering and denudation have acted upon the parent rock material to produce a thin layer of soil on earth .
Soil types are classified according to many more factors. They are classified on the basis of colour, depth, pH, productivity, texture and process of formation.
Soils of India: Classification and Characteristics –
Soil types according to depth are as follows:
1) Shallow Soil – Soil depth less than 22.5cm. Only shallow rooted crops are grown in such soil, e.g. Paddy, Nagli.
2) Medium deep soil – Soil depth is 22.5 to 45cm. Crops with medium deep roots are grown in this type of soil e.g. Sugar cane, Banana, Gram.
3) Deep soil – Soil depth is more than 45cm. Crops with long and deep roots are grown in this type a soil e.g. Mango, coconut
Importance of soil on earth –
- soil is very important for us because agriculture production is totally based on fertility of soil
- population on earth mostly reside in those area where soil is fertile .
- soil used for production of food grains and livelihood of people ,
Soil formation process and agents which play an important role in soil formation
there are many agents which play an important role in formation of soil like animals .insects ,rock material , relief and man .
- Parent material –
- the main material for soil formation comes from the mountains and rocks .
- the rocks are exposed to the process of weathering and suffer decay and decomposition .
- in this process the rocks are converted into fine grains which work as a base for soil formation
- for example -himalaya plays an important role in formation of soil in northern plain ,by deposition material from himalaya by himalayan rivers .
- relief also play an important role in formation of soil .one of the best example is steep slope of land .
- steep slope of land encourage swift flow of water and hinders the process of soil formation .
- area with low slope experience deposition and have deep layer of soil.
3. climate –
- climate is most important soil formation factor .climate play an important role in formation of soil.
- most important climatic factor is seasonal rainfall and temperature .
4.Natural Vegetation –
- Natural vegetation in india contain some of most fertile soil in india .because natural vegetation adds humus in soil thus increase soil fertility .decayed leaf of plant add humus in soil.
- so we can say that natural vegetation and soil has a close relationship .
The indian council of Agricultural Research (ICAR) has classified the soils of india into 8 Groups
- Alluvial Soils
- Black Soils
- Red and Yellow soils
- Laterite soils
- Mountains soils
- Desert or Arid Soils
- Saline Soils
- Peaty or Organic soils
1. Alluvial soils –Soils India: Classification and Characteristics
- the soil covers 40 percent part of total geographical area of India.
- This soil covers an area of 15 lakh sq km in India and mainly contributes in the development of agriculture.
- Alluvial soils are formed due to depositional work done by rivers in plains .valleys,flood plain and deltas
- The sutlej- Ganga basin has the largest depositional basin of Alluvial soils.
- This soil is very fertile in india and this plain is considered as the one of the most fertile areas of the world .
- the deltas of the Godavari.The Mahanadi,the Krishana ,the kavery are also abound by the Alluvial soil.
- Alluvial soil also found in the Assam valley ,Western plains , and Gujarat Plains.
- These soils can be sandy and loamy in nature .
- They are rich in potash but poor in phosphorous.in the upper ganga plain two different types of soils are formed
- Khadar – khadar is new alluvial soil which is deposited by floods every year annually and enrich soil.
- Bhangar – Bhangar represents the older alluvial soil which is deposited away from flood plains.
- color of alluvial soil differ from the light grey to ash grey.Alluvial soils are very important for the growth of the various crops like cereals and pulses.
2. Black soils – Soils India: Classification and Characteristics
- These soils are also known as Regur soils or Black cotton soils because these soils are famous for the cultivation of Cotton.
- The Black soils is formed by solidification of lava spread over large area of deccan plateau.
- Now days these soils are found in Karnataka,Maharashtra,MP,Gujarat ,AP and Tamil Nadu .
- in the lower part of Krishna and Godavari Basin n Black soils is quite deep.
- Black soils cover about 30 percent of the total area of country .
- Black soils are generally clayey,deep and impermeable .these soils has the capacity to retain moisture for the longer duration compare to other soils .
- when moisture and water evaporated then soils develop cracks .
- Black soils are very rich in minerals contents because these soils were formed due to volcanic activities.
- these soils contains high quantities of iron,Aluminium,Magnesium and lime.however they are poor in organic matter,nitrogen and Phosphorous.
3. Red and yellow Soils –Soils India: Classification and Characteristics
- These soils are formed by decomposition of Granite ( igneous) and Gneiss (metamorphic rocks )
- These soils are Reddish in color .because presence of iron oxide in it.
- These soils mainly found in Peninsular India.
- They cover almost whole Tamil Nadu,Karnataka,orissa and Andhra Pradesh.
- These soils also found in santhal Paragana and chhotta Nagpur Plateau.
- These soils lacks in Nitrogen,Phosphorous Acid and organic matter and are less fertile.
- They are mainly used for cultivation of Coarse grains ,pulses and oilseeds .
4.Laterite Soils – Soils India: Classification and Characteristics
- These soils are formed due to coming of dry and wet seasons alternately.
- laterite soils mainly found in those areas where rainfall occur more than 200 cms .
- Generally speaking soils with higher altitudes are more acidic than those of lower altitudes.
- More rainfall causes leaching away of laterite rocks because of which parts of silica and lime go down and compound or iron and aluminium are left in form of soils.
- these soils are found mainly in Hilly areas of Rajmahal .Eastern and Western Ghats ,Karnataka and some parts of orissa.
- these soils lack in nitrogen ,potash, Humus,the paucity of lime makes these soils acidic .so they are suitable for the cultivation of Tea.
5. Arid or Desert soils –Soils India: Classification and Characteristics
- The color of these soils range from Red to Brown .
- Most of these soils are sandy and saline .
- in some areas salt contents is very high that common salt is obtained from water by evaporation .
- These soils are rich in phosphorous and iron but deficient in humus and Nitrogen.
- These are infertile soils which are alkaline in nature .
- coarse cereals like jowar ,Bajara and ragi are produced in these soils .
6. Saline and Alkaline Soils –Soils India: Classification and Characteristics
- These soils are also called Reh, Usar, or Kallar.
- the saline soils also contains higher proportion of Sodium, Potassium And Magnesium.
- they are saline and contains more salts due to dry condition and poor drainage .
- these soils are found in Arid and semi arid and the Swampy and waterlogged areas.
- they are sandy and loamy and lack in nitrogen and calcium.
- saline soils are mainly found in Western Gujarat,Eastern coast deltas and sunderbans areas.
- in the green revolutions areas also alluvial soils are becoming saline soils due to excessive use of irrigation and fertilizers.
- These soils are deficient in Nitrogen and lime.
- in coastal areas coconut trees are found plenty in these soils.
7. Mountains Soils –Soils India: Classification and Characteristics
- these soils are found in those areas where high amount of rainfall occur .
- most of these forest soils are found in himalayan areas .
- these soils contain thin layer because of their development in mountian slopes.
- these soils are rich in fossils but they are under composed so humic acid formed and soils became acidic.
- these soils are poor in potash ,phosphorus and lime.
- these soils are affected by problem of soil erosion .
- mostly Tea,Coffee and fruits are grown in these soils.
8. Peaty or Organic Soils –Soils India: Classification and Characteristics
- these soils re found in those areas where high amount of rainfall occur .
- they have good growth of vegetation and are rich in humus and organic matter.
- peaty soils are heavy and brown in color but at several places these soils are alkaline in nature.
- these soils are too much Acidic.
- these soils are formed by the deposition of too much organic matter in marshy areas.