Geography Playlist
19 chapters • 0 completed
The Universe and the Earth
18 topics
Atmosphere and its composition
6 topics
Atmospheric Temperature
11 topics
Atmospheric Moisture
9 topics
Air Mass, Fronts & Cyclones
15 topics
Evolution of Earths Crust, Earthquakes and Volcanoes
23 topics
Interior of The Earth
14 topics
Landforms
25 topics
Geomorphic Processes
10 topics
Movement of Ocean Water
16 topics
Oceans and its Properties
12 topics
Climate of a Region
14 topics
Indian Geography - introduction, Geology
5 topics
Physiography of India
27 topics
Indian Climate
20 topics
Indian Drainage
32 topics
Soil and Natural Vegetation
13 topics
Mineral and Energy Resources, Industries in India
28 topics
Indian Agriculture
22 topics
Chapter 17: Soil and Natural Vegetation
Chapter TestSoil – Significance and Properties
Soil is the loose surface material forming the uppermost part of Earth’s crust, made of minerals, organic matter, gases, and water. It provides critical ecosystem services such as plant growth support, water filtration, carbon storage, and is the foundation of agriculture and infrastructure.
Soil is the loose surface material forming the uppermost part of Earth’s crust, made of minerals, organic matter, gases, and water. It provides critical ecosystem services such as plant growth support, water filtration, carbon storage, and is the foundation of agriculture and infrastructure.
Key Features of Soil
Aspect | Details |
---|---|
Definition | Loose surface material of Earth's crust, mix of minerals, organic matter, gases, water |
Ecosystem Role | Plant growth, water filtration, microorganism habitat, carbon storage |
Agriculture | Nutrient supply for crops (food, fibre, fuel) |
Infrastructure | Provides building materials and base for structures |
Texture | Defined by proportion of sand, silt, clay |
Loam | Balanced soil type with ideal texture for farming |
Mains Key Points
Prelims Strategy Tips
Soil Structure, Porosity, and Moisture
Soil structure refers to the arrangement of soil particles into aggregates called peds. Soil porosity determines water flow and aeration, while soil moisture types (hygroscopic, capillary, gravitational) influence plant growth and water availability.
Soil structure refers to the arrangement of soil particles into aggregates called peds. Soil porosity determines water flow and aeration, while soil moisture types (hygroscopic, capillary, gravitational) influence plant growth and water availability.
Types of Soil Structure
Type | Description |
---|---|
Granular | Formed by small spherical peds |
Blocky | Formed by large angular peds |
Platy | Thin, flat layers indicating compaction |
Columnar | Tall, pillar-like structures in arid soils |
Types of Soil Moisture
Type | Description | Availability to Plants |
---|---|---|
Hygroscopic Water | Thin film on soil particles held by molecular forces | Unavailable |
Capillary Water | Water in small pores, resists gravity | Available |
Gravitational Water | Excess water drains downward by gravity | Generally Unavailable |
Mains Key Points
Prelims Strategy Tips
Soil pH, Colour, and Profile
Soil pH indicates soil fertility and nutrient availability, soil colour reveals composition and formation, and soil profile represents vertical horizons (O, A, E, B, C) that together determine soil health and productivity.
Soil pH indicates soil fertility and nutrient availability, soil colour reveals composition and formation, and soil profile represents vertical horizons (O, A, E, B, C) that together determine soil health and productivity.
Soil pH and Plant Growth
pH Range | Nature | Effect on Plants |
---|---|---|
< 6 | Acidic | Nutrient deficiency; toxic elements may increase |
6–8 | Neutral to Slightly Alkaline | Optimal for most plants |
> 8 | Alkaline | Micronutrient deficiencies (e.g., iron, zinc) |
Soil Horizons
Horizon | Description |
---|---|
O Horizon | Organic matter (plants, animals) |
A Horizon | Topsoil enriched with organic matter |
E Horizon | Leached layer, loss of clay & oxides |
B Horizon | Accumulation layer; dense, clay-rich |
C Horizon | Parent material; below is bedrock |
Mains Key Points
Prelims Strategy Tips
Soil Development Processes
Soil development starts with regolith and proceeds through enrichment, removal, translocation, and transformation. These processes determine soil fertility, structure, and nutrient dynamics, making them central to pedology and agriculture.
Soil development starts with regolith and proceeds through enrichment, removal, translocation, and transformation. These processes determine soil fertility, structure, and nutrient dynamics, making them central to pedology and agriculture.

Processes of Soil Development
Process | Description | Example |
---|---|---|
Enrichment | Addition of organic/inorganic matter to soil | Humus accumulation |
Removal | Loss of material from soil body | Leaching of minerals |
Translocation | Movement of soil materials up/down profile | Eluviation & Illuviation |
Transformation | Change in soil material | Humification by microbes |
Mains Key Points
Prelims Strategy Tips
Factors Influencing Soil Formation
Soil formation is controlled by multiple natural and anthropogenic factors including parent material, climate, organisms, relief, time, and human activities. These factors determine soil colour, fertility, texture, horizons, and long-term sustainability.
Soil formation is controlled by multiple natural and anthropogenic factors including parent material, climate, organisms, relief, time, and human activities. These factors determine soil colour, fertility, texture, horizons, and long-term sustainability.
Factors Affecting Soil Formation
Factor | Influence |
---|---|
Parent Material | Determines soil texture, colour, and chemistry |
Climate | Rainfall causes leaching/salt buildup; temperature drives chemical processes |
Organisms | Vegetation and soil fauna add organic matter and restructure soil |
Relief | Slope gradient controls thickness of soil horizons |
Time | Long-term process; ~500 years for 2.5 cm topsoil |
Human Activities | Deforestation, farming alter soil fertility and erosion patterns |
Mains Key Points
Prelims Strategy Tips
Major Soil Types (Expanded Details)
Soils are classified into three broad categories: Zonal (influenced by climate and vegetation), Intrazonal (dominated by local conditions like drainage and parent rock), and Azonal (young soils with little profile development). Each type plays a unique role in agriculture, ecosystems, and human livelihoods.
Soils are classified into three broad categories: Zonal (influenced by climate and vegetation), Intrazonal (dominated by local conditions like drainage and parent rock), and Azonal (young soils with little profile development). Each type plays a unique role in agriculture, ecosystems, and human livelihoods.
Expanded Classification of Major Soils
Category | Soil Type | Properties | Regions |
---|---|---|---|
Zonal | Tundra | Frozen, poor organic matter | N. America, Eurasia |
Zonal | Podzol | Ashy, acidic, poor agriculture | Cool mid-latitudes, coniferous forests |
Zonal | Chernozem | Black, nutrient-rich, fertile | Russia, Ukraine, Canada, USA |
Zonal | Chestnut | Dark brown, steppe grassland, humus-rich | Mongolia, China, USA |
Zonal | Brunizem | Humus-rich, good for cereals | Prairie regions, USA, Europe |
Zonal | Seirozem | Grey desert soil, poor humus | Turkmenistan, W. USA |
Zonal | Latozols | Lateritic, red/yellow, iron-rich | Amazon, Brazil, SE Asia |
Intrazonal | Saline | Salt-affected, alkaline | Arid/semi-arid regions |
Intrazonal | Peat | Waterlogged, organic-rich | Cold, humid bogs/marshes |
Intrazonal | Calcareous | CaCO3-rich, alkaline | Limestone regions |
Azonal | Mountain/Scree | Rocky, shallow, erosion-prone | High mountains, moraines |
Azonal | Alluvial | Fertile, stratified | Indo-Gangetic plain, Yangtze basin |
Azonal | Glacial | Gravelly, poor humus | Glaciated regions |
Azonal | Loess | Windblown silt, fertile | China, Great Plains, Europe |
Mains Key Points
Prelims Strategy Tips
Soils of India – Factors Influencing Formation
The soils of India are formed by the combined influence of parent rock, relief, climate, and natural vegetation. Ancient crystalline rocks form red soils, Deccan basalt produces black regur soils, sedimentary rocks form calcareous soils, while relief and climate determine soil depth, erosion, and fertility.
The soils of India are formed by the combined influence of parent rock, relief, climate, and natural vegetation. Ancient crystalline rocks form red soils, Deccan basalt produces black regur soils, sedimentary rocks form calcareous soils, while relief and climate determine soil depth, erosion, and fertility.
Factors Influencing Soil Formation in India
Factor | Influence on Soil | Examples |
---|---|---|
Parent Material | Determines soil colour, texture, mineral composition | Basalt → Black soils, Granite → Red soils, Limestone → Calcareous soils |
Relief | Slope controls depth & erosion of soils | Chambal ravines (erosion), Northern Plains (deep fertile soils) |
Climate | Rainfall & temperature govern soil type | High rainfall → Laterite, Arid Rajasthan → Sandy soils |
Vegetation | Adds humus, increases fertility | Forest soils rich in organic matter |
Mains Key Points
Prelims Strategy Tips
Types of Soil in India
India has diverse soil types shaped by geology, relief, climate, and vegetation. The major soil types include Alluvial, Black, Red & Yellow, Laterite, Forest-Mountain, Arid, Saline-Alkaline, and Peaty soils. These soils vary in fertility, texture, mineral content, and crop suitability, making them critical for India’s agriculture and economy.
India has diverse soil types shaped by geology, relief, climate, and vegetation. The major soil types include Alluvial, Black, Red & Yellow, Laterite, Forest-Mountain, Arid, Saline-Alkaline, and Peaty soils. These soils vary in fertility, texture, mineral content, and crop suitability, making them critical for India’s agriculture and economy.
Major Soil Types in India
Soil Type | Distribution | Formation | Characteristics | Significance |
---|---|---|---|---|
Alluvial Soil | Covers ~40% of India; Indo-Gangetic-Brahmaputra plains, river valleys | Formed by deposition of sand, silt, clay by rivers | Khadar (new alluvium), Bhangar (old alluvium); sandy loam to clayey; rich in potash, poor in phosphorus; light grey to ash grey | Most fertile; crops: wheat, rice, jute, oilseeds, tobacco |
Black Soil (Regur) | Madhya Pradesh, Maharashtra, Andhra Pradesh, Gujarat, Tamil Nadu | Weathering of basalt (Deccan Trap), also gneiss and schist | Clayey, deep, impermeable; rich in lime, alumina, iron, magnesium; poor in nitrogen & humus; deep black to grey; cracks in dry season (self-ploughing) | Best for cotton; also wheat, millets, tobacco, sunflower, castor |
Red & Yellow Soil | Jharkhand, Odisha, Andhra Pradesh, Telangana, Chhattisgarh, Madhya Pradesh, Karnataka, Tamil Nadu (west) | Weathering of crystalline and metamorphic rocks | Red (iron oxides), yellow (hydrated); uplands → thin, sandy, porous; lowlands → thick, fertile; poor in nitrogen, lime, humus; rich in potash | Millets (upland); cotton, wheat, pulses, potatoes, tobacco (lowland) |
Laterite Soil | Karnataka, Tamil Nadu, Kerala, Assam, Odisha (hills), Madhya Pradesh | Intense leaching in high rainfall & temperature areas | Poor in humus, nitrogen, calcium; rich in iron, aluminium oxides; acidic | Cashew, tea, coffee, rubber, spices; also used for brick making |
Forest-Mountain Soil | Himalayas, Western & Eastern Ghats, hill slopes & valleys | Deposition of organic matter from forests | Loamy & silty in valleys; coarse on slopes; rich in humus, poor in lime & phosphorus | Tea, coffee, fruits, spices (peninsular); wheat, barley, maize (Himalayas) |
Arid/Desert Soil | Western Rajasthan (Thar), Punjab, Haryana (low rainfall areas) | Aeolian sand from Indus basin via monsoon winds | Sandy, saline, poor in humus; red-brown; calcareous layer restricts infiltration; high in phosphate | Millets, pulses (drought-resistant); reclaimable via irrigation |
Saline-Alkaline Soil | Arid/semi-arid areas; western Gujarat, Haryana, Punjab, eastern deltas, Sundarbans | Over-irrigation, saltwater intrusion | High in sodium, potassium, magnesium; infertile; poor in nitrogen & calcium | Legumes, paddy (with treatment); generally less productive |
Peaty Soil | Southern Uttarakhand, North Bihar, West Bengal, Odisha, Tamil Nadu (coastal) | High rainfall & humidity → high vegetative growth | Black, heavy; rich in humus & organic matter; poor in potash & phosphorus; acidic | Rice and jute cultivation |
Mains Key Points
Prelims Strategy Tips
Natural Vegetation of India
Natural vegetation refers to plant communities that grow naturally without human interference. India’s vegetation is highly diverse due to its varied climate, soil, altitude, and rainfall. The distribution ranges from evergreen forests in high rainfall areas to thorn forests in arid regions, and includes unique mangroves in coastal deltas.
Natural vegetation refers to plant communities that grow naturally without human interference. India’s vegetation is highly diverse due to its varied climate, soil, altitude, and rainfall. The distribution ranges from evergreen forests in high rainfall areas to thorn forests in arid regions, and includes unique mangroves in coastal deltas.
Spatial Distribution of Natural Vegetation in India
Rainfall Zone | Vegetation Type | Regions | Key Features |
---|---|---|---|
>200 cm | Tropical Evergreen Forests | Western Ghats, NE India, Andaman & Nicobar | Year-round green, no leaf-shedding season |
70–200 cm | Tropical Deciduous Forests | Central India, Himalayan foothills | Leaves shed in summer; teak & sal dominant |
<70 cm | Thorn & Scrub Forests | Rajasthan, Gujarat, Deccan Plateau | Cacti, thorny bushes, drought-adapted plants |
Coastal/Delta | Mangroves | Sundarbans, Godavari, Mahanadi deltas | Saline-tolerant vegetation (e.g., Sundari tree) |
Mains Key Points
Prelims Strategy Tips
Classification of Natural Vegetation in India
India’s natural vegetation is classified into five major types: Tropical Evergreen Forests, Tropical Deciduous Forests, Tropical Thorn Forests and Scrubs, Montane Forests, and Mangrove Forests. Their distribution depends on rainfall, temperature, soil, and altitude, each supporting unique biodiversity.
India’s natural vegetation is classified into five major types: Tropical Evergreen Forests, Tropical Deciduous Forests, Tropical Thorn Forests and Scrubs, Montane Forests, and Mangrove Forests. Their distribution depends on rainfall, temperature, soil, and altitude, each supporting unique biodiversity.
Comparison: Tropical Evergreen vs Deciduous Forests
Feature | Evergreen Forests | Deciduous Forests |
---|---|---|
Rainfall | >200 cm | 200–70 cm |
Leaf Shedding | No definite season | 6–8 weeks in summer |
Distribution | Western Ghats, NE India, Islands | Peninsular plateau, Ganga plains, Himalayan foothills |
Tree Species | Ebony, mahogany, rosewood, rubber | Teak, sal, sandalwood, neem |
Fauna | Elephants, monkeys, rhinoceroses | Tigers, lions, elephants, deer |
Mains Key Points
Prelims Strategy Tips
Tropical Thorn Forests and Montane Forests of India
Tropical thorn forests occur in arid and semi-arid regions with less than 70 cm rainfall, while montane forests appear in high-altitude areas, forming successive vegetation belts from tropical to tundra types. Both vegetation zones showcase adaptations to extreme climates and support unique biodiversity.
Tropical thorn forests occur in arid and semi-arid regions with less than 70 cm rainfall, while montane forests appear in high-altitude areas, forming successive vegetation belts from tropical to tundra types. Both vegetation zones showcase adaptations to extreme climates and support unique biodiversity.
Comparison: Tropical Thorn vs Montane Forests
Feature | Tropical Thorn Forests | Montane Forests |
---|---|---|
Rainfall | <70 cm | Varies by altitude |
Distribution | NW India, Gujarat, Rajasthan, MP | Himalayas, NE hills, southern highlands |
Vegetation | Acacias, palms, euphorbia, cactus | Oaks, chestnut, pine, deodar, fir, spruce |
Adaptations | Succulent stems, small leaves | Altitude-based zonation (tropical → tundra) |
Fauna | Camels, wild asses, lions, foxes | Snow leopard, yak, red panda, ibex |
Mains Key Points
Prelims Strategy Tips
Mangrove Forests and Medicinal Plants of India
Mangrove forests thrive in coastal tidal zones and river deltas, protecting coasts and supporting biodiversity like the Royal Bengal Tiger. India also has a rich tradition of medicinal plants, with over 500 species used in Ayurveda for treatments ranging from blood pressure to infections.
Mangrove forests thrive in coastal tidal zones and river deltas, protecting coasts and supporting biodiversity like the Royal Bengal Tiger. India also has a rich tradition of medicinal plants, with over 500 species used in Ayurveda for treatments ranging from blood pressure to infections.
Mangroves and Medicinal Plants – Key Facts
Aspect | Details |
---|---|
Main Mangrove Areas | Ganga, Mahanadi, Krishna, Godavari, Kaveri deltas |
Key Mangrove Tree | Sundari (durable hardwood) |
Iconic Fauna | Royal Bengal Tiger, crocodiles, turtles |
Total Medicinal Plants | ~2000 (Ayurveda); 500 commonly used |
Endangered Plants | 52 critically threatened; 49 endangered |
Notable Plants | Sarpagandha, Jamun, Arjun, Babool, Neem, Tulsi, Kachnar |
Mains Key Points
Prelims Strategy Tips
Status of Forest Cover in India (ISFR 2021)
According to the India State of Forest Report (ISFR) 2021, the total forest and tree cover of India is 24.62% of its geographical area. Madhya Pradesh has the largest forest cover, followed by Arunachal Pradesh, Chhattisgarh, Odisha, and Maharashtra. Forest cover at the national level increased by 1,540 sq km, with notable gains in Andhra Pradesh, Telangana, Odisha, Karnataka, and Jharkhand.
According to the India State of Forest Report (ISFR) 2021, the total forest and tree cover of India is 24.62% of its geographical area. Madhya Pradesh has the largest forest cover, followed by Arunachal Pradesh, Chhattisgarh, Odisha, and Maharashtra. Forest cover at the national level increased by 1,540 sq km, with notable gains in Andhra Pradesh, Telangana, Odisha, Karnataka, and Jharkhand.
India State of Forest Report 2021 – Key Statistics
Aspect | Details |
---|---|
Total Forest & Tree Cover | 24.62% of geographical area |
Top State (Forest Cover) | Madhya Pradesh |
Other Major States | Arunachal Pradesh, Chhattisgarh, Odisha, Maharashtra |
Increase in Forest Cover | 1,540 sq km |
Tree Cover Growth (2011–2021) | 90,844 → 95,748 sq km (4,904 sq km increase) |
Special Inclusion | Assessment of Tiger reserves, corridors, decadal change |
Agency | Forest Survey of India (FSI), under MoEFCC |
Mains Key Points
Prelims Strategy Tips
Chapter Complete!
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