What Are Different Types Of Soil In India?
All types of soil in India display a wide diversity because of the variation in the climate, relief and vegetation. Soil is the thin surface layer on the earth composed of mineral and organic matter supporting the growth of plants. Soils in India display wide diversity because of the variation in geology, climate, relief and vegetation. On the basis of genesis, color, composition and location, the Indian council of Agricultural Research (ICAR) has classified the type of soil in India into the following 8 categories:
- Alluvial Soil
- Laterite Soil
- Black Soil
- Red Soil
- Red And Yellow
- Forest / mountain Soil
- Saline And Alkaline Soil
- Peaty / Organic Soil
[Also Read: The Controls Affecting The Climate Of India]
Alluvial Soil In India
- Alluvial Soil is a major constituent of types of soil in India. This is the most important soil group of India.
- These are the most productive soils and are depositional in nature as they are transported by streams and rivers. They are largely sandy and loamy in texture and are mixed with both silt and clay.
- They are sufficient in Phosphorus and Potasium, but lack nitrogen and organic matter. These alluvial soils are divided into Bangar (old alluviam) and Khadar (new alluviam).
- Most of the alluvial soils are created by the sediments deposited by the rivers of Indo-Gangetic Plains. Some alluvial soils in the coastal areas are formed by the sea waves.
- They are immature soils with weak profiles (AZONAL). Their chemical composition makes this group of soils as one of the most fertile in the world.
Occurrence: From the Great Indo- Gangetic Plain starting from the Punjab in the West to West Bengal and Assam in the East. They also occur in the deltas of Mahanadi. Godavari, Krishna and Cauvery. Some alluvial soils are found in Narmada and Tapi valleys. Parts in north Gujarat also have some cover of alluvial soils.
The alluvial soils are divided geologically into
(i) Bhangar (old alluvium) and Khadar (new alluvium)
(ii) Bhabbar (in the foothills of Shivaliks)
(iii) Tarai (in the foothills of Shivalik)
Their chemical composition makes Highly productive soils devoted to the cultivation of wheat, rice, pulses, sugarcane, jute, oil seeds, fodder, vegetables and orchards.
Black Soil In India
- These are the typical soils developed on the basaltic rocks of the Deccan plateau.
- The region includes Maharashtra, South and East Gujarat, Western M.P., Northern Karnataka, Northern Andhra Pradesh, North East Tamil Nadu, South East Rajasthan etc. It spreads over 5 lakh km2 area, and is known as ‘Rugur’ or ‘Black Soil’.
- Regur Soil varies in colour from black to chestnut brown. This soil is rich in iron, lime and aluminium content , and has high moisture retentive capacity.
- This soil lack nitrogen, phosphorus and organic matter. These are finely grained and become sticky when wet and develop cracks when dry.
- Apart from cotton crops like groundnut tobacco sugarcane, pulses and oil seeds are also grown in this soil. This soil is also suitable for growing these commodities because of its high moisture retentive capacity.
Red Soil In India
- These soils have been formed through the weathering of granite gneiss and shiest rocks.
- The colour is red, due to the presence of iron oxides.
- It is typically found in Tamil Nadu, Karnataka, Andhra Pradesh, Odhisha and Chhotangapur plateau of Jharkhand have large expanses of this soil.
- This soil lacks nitrogen, phosphorus and humus. It is mainly suitable for the cultivation of coarse grains pulses, tobacco, millets, potatoes and fruits and oil seeds.
Laterite Soil In India
- These are typical soils of the tropical regions with heavy seasonal rainfall alternating with dry season.
- Lime and silica are leached away with rains and soils rich in iron oxide and aluminium compounds are left behind. The organic matter nitrogen, phosphate and calcium are low in these soils.
- At some places, phosphate content and humus may be high. They are found in eastern and western Ghats, Rajmahal hills, parts of Kerala and Karnataka, parts of Chhotanagpur, Meghalaya plateau and Assam .
- The soil is generally of low fertility in which only coarse grains, pulses and oil seeds can be cultivated.
- When irrigated, some laterites are suitable for growing plantation crops like tea, coffee, rubber and coconut etc.
- These soils have a unique distinction of providing valuable building material. Laterite means brick color.
Forest Soil / Mountain Soils
- Formed in the forest and hilly areas with sufficient rainfall. This soil is found mainly in the Himalayan region, Western Ghats, Eastern Ghats and hilly regions of Peninsular India.
- They are rich in humus but deficient in potash, phosphorous and lime. If treated with fertilizers, they are especially suitable for plantations of tea, coffee, spices and tropical fruits in Karnataka, Tamil Nadu and Kerala and wheat, maize, barley and temperate fruits in Jammu and Kashmir and Himachal Pradesh.
- The problem of soil erosion is getting acute in regions having this soil due to deforestation and other developmental activities.
- They are mainly found in Rajasthan, southern Punjab and Haryana and northern Gujarat.
- Being sandy, the water retaining capacity of these soils is low.
- These soils are rich in phosphate and poor in humus content. Wherever irrigation is available, they are devoted to cotton and wheat.
- Millets, maize and pulses are the main crops grown in them.
- Due to dry climate, high temperature and accelerated evaporation there is always a paucity water.
- Thus, these soils lack moisture and humus content. Iron and phosphorus content is normal. Being sandy, the water retaining capacity of these soils is low.
- They are found in west Rajasthan, Southern Punjab and Haryana and north Gujarat.
- With irrigation these soils can be better utilized for cultivation.
Saline And Alkaline Soil In India
- Also known as ‘Usara’ soils, they contain a larger proportion of sodium, potassium and magnesium.
- They occur in arid and semiarid regions and water logged and swampy areas. They acquire salts largely because of dry climate and poor drainage. Infertile soils are formed due to capillary action.
- In some places they are also known as reh, kallar, usar, thur, karl, chopan.
- They are found on southern Punjab and Haryana, west Rajasthan, Kerala coast, Sunderban area etc. This is the least found category among all types of soil in India.
Peaty Soil / Organic Soil
- They are found in the area of heavy rainfall where there is a good grown of vegetation, hence rich in humus and organic content.
- This type of soiloccurs in the northern Bihar, southern Uttaranchal ( Almora district) and coastal areas of west Bengal, Orissa, Kottayam and Alapuha districts of Kerela and parts of Tamil Nadu.
- After the rainy season the regions under this soil is put to paddy cultivation.
[Also Read: The Controls Affecting The Climate Of India]
Soil Survey Of India
Established in 1958 under Ministry of Agriculture, Government of India, All India Soil & Land Use Survey (renamed as Soil & Land Use Survey of India), is a premier institution in the field of soil survey and land resource mapping in the country. Soil and land survey is conducted for testing ground conditions, doing ground investigation and in-situ testing of soils. The information gathered in a soil survey can be used to predict or estimate the potentials and limitations and behaviours of the soils under different circumstances and their potential uses.
Thus soil surveys can be used to plan the development of new lands or to evaluate the conversion of land to new uses. There are 3 primary types of soil surveys namely – (a) Detailed survey (b) Reconnaissance survey, and (c) Detailed-reconnaissance survey. As soil quality cannot be directly measured, some evaluation indicators are used to determine its quality. These indicators provide clues about how well the soil can function. Indicators can be physical, chemical, and biological characteristics. Indicators can be assessed by qualitative or quantitative techniques. On the basis of these indicators soils can be classified into 4 types – sandy, loamy, silt and clay.
Types Of Soil In India Map
Conclusion On Types Of Soil In India
Overall, the diverse range of soil types in India reflects the country’s rich agro-ecological diversity. Understanding the characteristics and properties of different soils is crucial for sustainable land management, appropriate crop selection, and efficient agricultural practices. With proper soil conservation and management techniques, India can harness the potential of its soils to ensure food security, economic development, and environmental sustainability in the years to come.
Layers Of Soil
There are several distinct layers of soil, commonly referred to as soil horizons. These soil horizons form through a process known as pedogenesis. All layers have unique characteristics and play a vital role in supporting plant growth and other ecosystem functions. The major soil layers, or horizons, can be summarized as follows:
- O Horizon (Organic Layer): This is the uppermost layer and it consists of organic matter such as decaying plant material, leaf litter, and other organic residues. It is the most nutrient-rich layer and serves as a source of nutrients for plants. The thickness of the O horizon varies depending on factors like climate, vegetation, and decomposition rates.
- A Horizon (Topsoil): Also known as the topsoil, this layer is rich in organic matter, minerals, and nutrients. It is the primary zone for plant roots and contains a high concentration of beneficial soil microorganisms. The A horizon is typically darker in colour due to the presence of organic material and is crucial for agricultural productivity.
- E Horizon (Eluviation Layer): The E horizon is found beneath the A horizon in certain soil profiles. It is characterized by the leaching or washing out of minerals like iron, aluminium, and clay particles through the percolation of water. This results in a lighter colour and a lower concentration of nutrients compared to the A horizon.
- B Horizon (Subsoil): The B horizon is a subsurface layer that accumulates materials leached from the E horizon above. It often contains minerals, clay, and nutrients that have been transported from the upper layers. The B horizon exhibits distinct colour variations, and its composition can vary depending on the parent material and the specific soil formation processes.
- C Horizon (Weathered Parent Material): This layer is composed of partially weathered rock fragments and minerals, often referred to as the parent material. The C horizon is less affected by biological activity and shows limited weathering compared to the upper layers. It serves as a transitional zone between the soil and the underlying bedrock.
- R Horizon (Bedrock): The R horizon represents the unweathered bedrock or consolidated rock layer. It lies beneath the C horizon and is composed of solid rock material. The depth of the R horizon varies significantly, and it may or may not be present in every soil profile.
It is important to note that not all soil profiles exhibit all of these horizons. The presence and characteristics of each layer depend on factors such as climate, parent material, vegetation, topography, and the length of time soil formation has occurred. Soil scientists analyse these layers to understand soil properties, fertility, drainage capabilities, and suitability for various land uses, including agriculture, forestry, and construction.
Soil Profile Diagram / Layers Of Soil Diagram
How Is Soil Formed?
Soil formation, also known as pedogenesis, is a complex process that occurs over long periods of time through the interaction of various factors. The formation of soil involves the weathering of rocks and minerals, the addition of organic matter, the influence of climate and organisms, and the effects of topography. The following are the key processes involved in soil formation:
- Weathering: Weathering causes the breakdown and decomposition of rocks and minerals through physical, chemical, and biological processes. Physical, chemical and biological processes bring about some key changes that are instrumental in the formation of soil. Physical weathering causes physical disintegration of rocks into smaller particles, while chemical weathering involves the alteration of rock minerals through chemical reactions. Biological weathering occurs through the actions of plants, animals, and microorganisms, which contribute to the breakdown of rocks and the addition of organic matter.
- Parent Material: The type of soil created depends a lot upon the parent material. The parent material is the initial material from which soil forms. It can be derived from the weathering of underlying bedrock or from materials deposited by glaciers, wind, water, or volcanic activity. The composition of the parent material influences the mineral content and texture of the resulting soil.
- Organic Matter Accumulation: Organic matter, such as dead plants, leaves, roots, and animal remains, accumulates on the soil surface. This organic material undergoes decomposition by soil organisms, including bacteria, fungi, insects, and earthworms. The decomposition process adds nutrients and contributes to the formation of humus, which improves soil structure, water-holding capacity, and nutrient retention.
- Soil Horizons: Over time, distinct layers, or horizons, develop within the soil profile as a result of different soil-forming processes. These horizons, such as the O, A, E, B, C, and R horizons mentioned earlier, exhibit variations in color, texture, organic matter content, and mineral composition.
- Climate: Climate plays a significant role in soil formation. Temperature and rainfall patterns influence the rate of weathering, the decomposition of organic matter, and the leaching of minerals. Cold and wet climates promote physical weathering and leaching, while warm and humid climates accelerate chemical weathering and organic matter decomposition.
- Organisms: Though a part of biological weathering, organisms play a vital role in the formation of soil. Soil organisms, including plants, microorganisms, insects, earthworms, and burrowing animals, contribute to soil formation. Plant roots penetrate the soil, breaking up rocks, and facilitating the weathering process. Microorganisms and decomposers break down organic matter, releasing nutrients. Burrowing animals create channels for air and water movement, aiding in the mixing of soil materials.
- Time: Time is a critical factor in the process of soil formation. Soil formation is a slow process that occurs over thousands to millions of years. Thus it becomes imperative that soil is conserved at all costs. The rate of soil formation depends on factors such as climate, vegetation, topography, and parent material. Older soils tend to have more developed horizons and greater fertility compared to younger soils.
These processes interact and occur simultaneously, leading to the gradual formation of soil. The resulting soil properties, such as texture, fertility, drainage, and pH, influence its suitability for various land uses, including agriculture, forestry, and habitat for plants and animals. Sustainable land management practices aim to preserve and enhance soil quality to ensure its continued productivity and ecological functions.
Soils are classified on the basis of texture, composition, genesis and location. On these grounds soils in India are classified or divided into 8 types.
Different types of soils in India are:
Red And Yellow
Forest / mountain Soil
Saline And Alkaline Soil
Peaty / Organic Soil