Types of Soil in India – UPSC Indian Geography Notes

Historically, Soil in India was categorized into two groups: Urvara, representing fertile soils, and Usara, representing sterile soils.

However, the National Bureau of Soil Survey and Land Use Planning, an institute under the Indian Council of Agricultural Research (ICAR), conducted extensive studies on Indian soils and classified them into eight types based on their formation, color, composition, and location. These soil types are briefly described below.

Table of Contents

Alluvial Soil

Extent: Alluvial soil covers a significant portion of the total land area in India. It is estimated to occupy around 45% of the country’s total geographical area.
Distribution: Alluvial soil is predominantly found in the northern plains of India, particularly in the states of Uttar Pradesh, Bihar, West Bengal, Punjab, Haryana, and parts of Rajasthan. It is also present in parts of Gujarat, Madhya Pradesh, Maharashtra, and Tamil Nadu.
Thickness: The depth of alluvial soil can vary widely across different regions. It can range from a few meters to more than 20 meters in depth.
Texture: The texture of alluvial soil in India varies depending on the region. In general, it is characterized by a mixture of sand, silt, and clay in varying proportions. The texture can range from sandy loam to clayey loam.
Fertility: Alluvial soil is highly fertile and supports intensive agriculture. It contains a good amount of organic matter and essential nutrients like nitrogen, phosphorus, and potassium. The fertility of alluvial soil contributes to the high agricultural productivity in the regions where it is found.
Crops: Alluvial soil is suitable for a wide range of crops. In the northern plains, it supports the cultivation of crops such as rice, wheat, sugarcane, cotton, jute, maize, and oilseeds. In the delta regions, it is conducive to the cultivation of rice and other water-intensive crops.
Irrigation: The presence of alluvial soil in the fertile plains of India, combined with the network of rivers and canals, facilitates irrigation. The availability of water for irrigation has further boosted agricultural productivity in these regions.
Challenges: While alluvial soil is highly productive, it also faces challenges in certain areas. Waterlogging and salinity are issues in some regions, particularly where drainage systems are inadequate.

Black Soil

Distribution: Black soil is predominantly found in the Deccan Plateau region of India, covering parts of Maharashtra, Gujarat, Madhya Pradesh, Karnataka, Andhra Pradesh, and Tamil Nadu. It is particularly extensive in the states of Maharashtra and Gujarat.
Formation: Black soil is formed from basaltic lava rocks and is rich in iron, magnesium, and lime. The weathering of these rocks over time results in the formation of black soil.
Texture: Black soil has a unique granular texture and is known for its high water-holding capacity. When wet, it becomes sticky and molds easily. However, it also tends to crack when it dries.
Fertility: Black soil is highly fertile and ideal for agriculture. It contains a good proportion of clay, organic matter, and essential nutrients like calcium, magnesium, potassium, and phosphorus. This fertility makes it suitable for a wide range of crops.
Crops: Black soil is particularly suitable for the cultivation of cotton, hence its alternative name “black cotton soil.” It is also used for growing crops like wheat, soybeans, millets, sorghum, tobacco, and certain fruits and vegetables.
Irrigation: Black soil has good water retention capacity and drains slowly. It can hold moisture for a long time, which is beneficial during the dry season. However, excessive water can cause waterlogging and restrict root development.
Problems: Black soil can pose challenges such as poor drainage, waterlogging, and soil erosion if not managed properly. It is also prone to cracking during dry periods, which can affect crop growth.
Area Covered: Black soil covers approximately 26% of the total land area in India. It is one of the major soil types in the country.
Fertilizer Requirements: Black soil generally has good nutrient-holding capacity, but in certain regions, additional fertilizers may be required to maintain optimal soil fertility for sustained agricultural productivity.

Red Soil

Composition: Red soil is formed by the weathering of ancient crystalline rocks, such as granite, gneiss, and schist. It has a high proportion of iron oxide, which gives it a reddish color.
Distribution: Red soil is predominantly found in the Deccan Plateau region of India, covering states like Tamil Nadu, Karnataka, Andhra Pradesh, Maharashtra, and parts of Odisha and Chhattisgarh.
Fertility: Red soil is relatively less fertile compared to alluvial soil. It lacks inorganic matter and essential nutrients, especially nitrogen, phosphorus, and organic carbon. However, with proper nutrient management and irrigation, it can support agricultural activities.
Crops: Red soil is suitable for crops like millets, pulses, cotton, groundnut, tobacco, and some horticultural crops. It is known for its suitability for growing peanuts (groundnuts).
Characteristics: Red soil has a coarse texture, low water-holding capacity, and poor nutrient-retention capability. It is well-drained due to its sandy nature.
Area: Red soil covers an estimated area of around 3.5 lakh square kilometers in India.

Yellow Soil

Composition: Yellow soil is formed by the weathering of crystalline rocks and is characterized by a yellowish or pale color. It contains a relatively higher proportion of iron and aluminum hydroxides.
Distribution: Yellow soil is mainly found in the eastern and central parts of India, including parts of Odisha, Jharkhand, Chhattisgarh, Madhya Pradesh, and Telangana.
Fertility: Yellow soil is moderately fertile and contains more nutrients compared to red soil. It has better moisture-retaining capacity and is more suitable for agriculture.
Crops: Yellow soil supports the cultivation of crops like rice, wheat, millets, pulses, oilseeds, and vegetables. It is particularly suitable for rice cultivation due to its water-retentive nature.
Characteristics: Yellow soil has a relatively finer texture than red soil, with good moisture retention. It is often used for rain-fed agriculture.
Area: The exact area covered by yellow soil in India is not readily available, but it is found in significant portions of the central and eastern regions.

Laterite Soil

Composition: Laterite soil is rich in iron and aluminum oxides. It has a high percentage of clay and silica along with smaller amounts of potash, lime, and magnesia. The presence of iron oxide gives laterite soil a reddish or yellowish color.
Acidity: Laterite soil is generally acidic due to leaching caused by heavy rainfall. The pH level ranges from 4 to 6, making it unsuitable for certain crops that prefer neutral or alkaline soil.
Drainage: Laterite soil has poor drainage due to its high clay content. It retains water for a longer duration, leading to waterlogging in some areas.
Distribution: Laterite soil is widely distributed in India, particularly in the Western Ghats, Eastern Ghats, parts of Odisha, Karnataka, Kerala, Tamil Nadu, and the northeastern states. It is also found in some coastal regions.
Crops: The acidic nature and poor drainage of laterite soil make it less suitable for traditional agriculture. However, certain crops like cashew nuts, tea, coffee, rubber, and spices (such as pepper and cardamom) thrive in laterite soil. These crops have adapted to the specific characteristics and nutrient composition of this soil type.
Soil Fertility: Laterite soil is generally less fertile compared to alluvial soil. It is low in essential nutrients such as nitrogen, phosphorus, and potassium. However, with proper soil management practices and nutrient supplementation, agricultural productivity can be improved.
Erosion: Laterite soil is prone to erosion due to its sandy and loamy texture. Heavy rainfall can wash away the topsoil, leading to soil degradation and reduced fertility.
Terracing: In hilly regions with laterite soil, farmers often practice terracing to prevent soil erosion. Terracing involves creating steps or leveled areas on sloping land, reducing water runoff and soil loss.

Arid Soil

Composition: Arid soils are typically sandy and contain a significant amount of sand particles. They have low organic matter content and are poor in nitrogen and other nutrients. The soil lacks clay and silt particles, resulting in a loose and friable texture.
pH Level: Arid soils are generally alkaline or saline in nature, with pH values ranging from slightly alkaline (pH 7.5-8.5) to strongly alkaline (pH above 8.5). The high alkalinity can affect plant growth and restrict the choice of crops.
Nutrient Content: Arid soils are deficient in essential plant nutrients such as nitrogen, phosphorus, and organic matter. The low nutrient availability poses challenges for agriculture and requires proper soil management practices, including nutrient supplementation.
Water Holding Capacity: Due to the coarse texture and low organic matter content, arid soils have low water holding capacity. They cannot retain water effectively, leading to fast drainage and drying out quickly.
Salinity: Many arid soils in India suffer from salinity problems, primarily due to the accumulation of salts in the soil profile. This salt accumulation hampers plant growth and limits crop production. Proper soil reclamation and management techniques are necessary to mitigate salinity issues.
Vegetation: Arid soils support xerophytic vegetation, which consists of plants adapted to survive in arid conditions with limited water availability. Typical vegetation includes thorny shrubs, cacti, and drought-resistant grasses.
Distribution: Arid soils are found in regions with low rainfall, including parts of Rajasthan, Gujarat, Haryana, Punjab, and parts of the Deccan Plateau. These areas are characterized by a semi-arid to arid climate, with hot and dry conditions.
Agricultural Challenges: Cultivation in arid soil regions is challenging due to water scarcity, nutrient deficiencies, alkalinity, and salinity issues. However, with appropriate irrigation techniques, use of drought-resistant crop varieties, and soil management practices, limited agriculture is possible in these areas.

Forest Soil

Composition: Forest soil is rich in organic matter due to the continuous deposition and decomposition of plant material such as leaves, twigs, and fallen trees. It has a high humus content, which contributes to its dark brown to black color.
Texture: The texture of forest soil varies depending on factors like parent material, climate, and vegetation. It can range from sandy loam to clayey loam, with a good proportion of silt and clay particles. The presence of organic matter improves the soil structure and water-holding capacity.
Acidity: Forest soils in India tend to be slightly acidic to neutral in nature. The pH level varies depending on factors like tree species, climate, and organic matter decomposition rates.
Nutrient Content: Forest soil is rich in nutrients, especially organic carbon, nitrogen, phosphorus, and potassium. The continuous recycling of organic matter in the forest ecosystem contributes to the nutrient richness of the soil.
Moisture Retention: Forest soil has good moisture retention capacity due to its high organic matter content. It helps in regulating water availability for plant growth and supports the thriving of various forest vegetation.
Biodiversity Support: Forest soils provide an ideal habitat for a wide range of flora and fauna. The rich nutrient content and moisture retention capacity support the growth of diverse plant species, including trees, shrubs, and understory vegetation. It also facilitates the presence of numerous soil organisms and microorganisms.
Erosion Control: Forest soils play a crucial role in preventing soil erosion. The dense vegetation cover in forests helps in stabilizing the soil, reducing surface runoff, and promoting water infiltration.
Distribution: Forest soil is found in various forested regions across India, including the Western Ghats, Eastern Ghats, Himalayan foothills, northeastern states, and central Indian forests

Saline Soil or Usara Soil

Distribution: Saline soil is found in different parts of India, primarily in the northwestern and western regions, including states like Gujarat, Rajasthan, parts of Punjab, Haryana, and Uttar Pradesh. Coastal regions such as parts of Gujarat, Maharashtra, and Andhra Pradesh may also have saline soil due to the influence of seawater.
Salinity levels: Saline soils have a high concentration of salts, especially sodium chloride (common salt), which can render the soil unsuitable for most crop cultivation. The electrical conductivity (EC) of saline soil is typically above 4 dS/m (decisiemens per meter) and sometimes even exceeds 40 dS/m.
Causes of salinity: The main causes of soil salinity in India are inadequate drainage, excessive irrigation with poor-quality water, high evaporation rates, and natural salt deposits. In some cases, seawater intrusion in coastal areas can also contribute to salinity.
Effects on agriculture: Saline soil poses significant challenges to agricultural productivity. Excessive salt content can hinder water uptake by plant roots, leading to poor growth, reduced yields, and even plant death. It also affects the soil structure, making it less permeable and more prone to waterlogging.
Crop tolerance: Certain salt-tolerant crops and plants can be grown in saline soil. Examples include halophytic plants like saltbush, mangroves, and some varieties of barley, wheat, and millets. However, crop options are limited compared to non-saline soils.
Remedial measures: Several measures can be undertaken to mitigate the effects of saline soil. These include leaching the salts through proper drainage, implementing efficient irrigation practices, using suitable amendments like gypsum to improve soil structure, adopting salt-tolerant crop varieties, and planting trees or windbreaks to reduce evaporation.
Reclamation: Reclaiming saline soil is a long-term process that involves a combination of measures such as land leveling, soil flushing, application of soil amendments, and adopting appropriate cropping patterns. Reclamation efforts aim to restore the soil’s fertility and reduce salt content to levels suitable for crop cultivation.

Peaty Soil

Characteristics: Peaty soil is composed mainly of partially decomposed organic matter, such as plant material and vegetation debris. It has a dark brown to black color and a high organic content.
Texture: Peaty soil has a spongy and fibrous texture due to the presence of organic matter. It is usually soft and easily compressible.
Distribution: Peaty soil is found in regions with high rainfall and waterlogging conditions. In India, it is predominantly found in the coastal areas of Kerala, Tamil Nadu, West Bengal, and parts of the northeastern states.
Crops: Peaty soil is not very suitable for agriculture due to its high organic content, poor drainage, and acidic nature. However, some crops like rice, water chestnut, and certain vegetables can be grown in localized areas with proper management.

Marshy Soil

Characteristics: Marshy soil is characterized by its high water content and poor drainage. It is usually dark in color, heavy, and has a high clay content.
Texture: Marshy soil has a heavy and sticky texture due to the presence of fine clay particles. It becomes waterlogged easily and retains water for long periods.
Distribution: Marshy soil is found in low-lying areas, deltas, and coastal regions where water accumulates and drains slowly. In India, it is found in the Sundarbans region of West Bengal, parts of Assam, and other coastal areas.
Crops: Marshy soil is not suitable for most agricultural crops due to its poor drainage and high water content. However, it supports the growth of certain crops like paddy, lotus, and some aquatic plants

Classification of Indian Soil as per USDA

The Indian Council of Agricultural Research (ICAR) has categorized Indian soil according to its properties and attributes in accordance with the Soil Taxonomy system of the United States Department of Agriculture (USDA).

FAQs

Q1. What is Alluvial soil and where is it found in India?

Ans. Alluvial soil is known for its high fertility and is found in the northern plains of India. It is ideal for the cultivation of various crops like grains, sugarcane, and oilseeds.

Q2. Where is Black soil found in India and what crops is it suitable for?

Ans. Black soil, also known as Regur soil, is predominantly found in the Deccan Plateau region, particularly in states like Maharashtra, Gujarat, and Madhya Pradesh. It is suitable for the cultivation of cotton.

Q3. What is water erosion and how does it affect Indian soil?

Ans. Water erosion refers to the wearing away of soil by water. In India, this is a common phenomenon in areas with high rainfall, leading to loss of topsoil and nutrient depletion, affecting agricultural productivity.

Q4. How does wind erosion impact Indian soil and agriculture?

Ans. Wind erosion involves the movement of soil by the force of wind. In certain arid and semi-arid regions of India, wind erosion is a significant problem, leading to the loss of fertile topsoil and making the land less suitable for cultivation.

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