Soil Types MCQs Quiz | Class 10

Understanding India’s Major Soil Types

Soils are one of the most important natural resources, forming the basis for agriculture and supporting various ecosystems. India, with its diverse relief features, landforms, climatic realms, and vegetation types, has a wide variety of soils. Understanding these soil types is crucial for agricultural planning and resource management.

1. Alluvial Soils

Alluvial soils are the most widespread and important soil type in India. They are formed by the deposition of sediments by rivers, making them highly fertile. These soils are found in the Northern Plains (Indus, Ganga, Brahmaputra valleys) and also in the deltas of the Mahanadi, Godavari, Krishna, and Kaveri rivers.

• Formation: Deposited by Himalayan rivers (Indus, Ganga, Brahmaputra) and coastal rivers.
• Characteristics:
  • Varying proportions of sand, silt, and clay.
  • Rich in potash, phosphoric acid, and lime, making them ideal for the growth of sugarcane, paddy, wheat, and other cereal and pulse crops.
  • Highly fertile.
• Types:
  • Khadar: New alluvial soil, found in floodplains, renewed almost every year, and very fertile.
  • Bhangar: Old alluvial soil, found above the floodplains, has a higher concentration of Kankar nodules (calcareous concretions). Less fertile than Khadar.
• Distribution: Northern Plains, Rajasthan, Gujarat, Eastern Coastal Plains.

2. Black Soils (Regur Soils)

Black soils are famous for their capacity to hold moisture and are ideal for growing cotton, hence also known as Black Cotton Soil. These soils are primarily found in the Deccan Trap region.

• Formation: Formed from weathering of basaltic rocks (lava flows).
• Characteristics:
  • Black in color and known as Regur soils.
  • Made up of extremely fine, clayey material, making them well-known for their moisture-retentivity.
  • Rich in calcium carbonate, magnesium, potash, and lime. Poor in phosphoric content.
  • Develop deep cracks during hot weather, which helps in the aeration of the soil.
  • Sticky when wet and difficult to work unless tilled immediately after the first shower or during the pre-monsoon period.
• Distribution: Deccan Trap region spread over Maharashtra, Saurashtra, Malwa, Madhya Pradesh, and Chhattisgarh. Also found along the Godavari and Krishna valleys.
• Major Crops: Cotton, sugarcane, jowar, wheat, groundnut, tobacco.

3. Red and Yellow Soils

Red soils develop on crystalline igneous rocks in areas of low rainfall in the eastern and southern parts of the Deccan Plateau. They are often found alongside yellow soils.

• Formation: Formed from the weathering of old crystalline and metamorphic rocks.
• Characteristics:
  • Reddish color due to the diffusion of iron in crystalline and metamorphic rocks.
  • Appears yellow when it occurs in a hydrated form.
  • Generally poor in nitrogen, phosphorus, and humus content.
  • Fine-grained red and yellow soils are usually fertile, while coarse-grained ones in dry uplands are poor in fertility.
• Distribution: Eastern and Southern parts of the Deccan Plateau, Odisha, Chhattisgarh, and parts of the Middle Ganga Plain, and along the piedmont zone of the Western Ghats.
• Major Crops: Millets, pulses, groundnuts, potatoes.

4. Laterite Soils

Laterite soils are formed under conditions of high temperature and heavy rainfall. This leads to intensive leaching of soluble salts by monsoonal rains.

• Formation: Developed in areas with high temperature and heavy rainfall, undergoing intense leaching due to tropical rains.
• Characteristics:
  • The humus content of the soil is low because most of the microorganisms, particularly decomposers like bacteria, get destroyed due to high temperature.
  • Generally acidic and coarse in texture.
  • Poor in organic matter, nitrogen, phosphate, and calcium.
  • After adopting appropriate soil conservation techniques, these soils are useful for growing tea, coffee, and cashew nuts.
• Distribution: Primarily in Karnataka, Kerala, Tamil Nadu, Madhya Pradesh, hilly areas of Odisha, and Assam.
• Major Crops: Tea, coffee, cashew nuts, tapioca.

Quick Revision Table: Major Soil Types

Practice Questions for Further Study

1. Explain the difference between Khadar and Bhangar soils.
2. Why are Black soils considered ideal for cotton cultivation?
3. Describe the geographical conditions required for the formation of Laterite soils.
4. What causes the distinct reddish color of Red soils?
5. Name three important nutrients typically found abundantly in Alluvial soils.