SOIL

Soil Overview

  • Soil is the upper layer of earth where plants, trees, and other organisms grow.

  • It provides key ecosystem services, such as:

    • Storing and filtering water

    • Vital role in the carbon cycle

    • Rich in minerals necessary for plant growth

Types of Soil

  1. Alluvial Soil

    • Formed by sediment deposits from rivers.

    • Rich in phosphoric acid, potash, and lime.

    • Types:

      • Old Alluvial: Known as Bangar.

      • New Alluvial: Known as Khaddar.

    • Area: Northern plains from Punjab to West Bengal, including river deltas.

    • Crops: Rice, Ragi, Sugarcane, Rubber, etc.

  2. Laterite Soil

    • Covers 3.7% of total land area.

    • Rich in Iron Oxide, low in humus.

    • Found in regions with heavy rainfall and alternating dry/wet periods (Western Ghats, Eastern Ghats).

  3. Red Soil

    • Comprised of weathered geological material rich in Iron-oxide.

    • Poor in lime, phosphates, and nitrogen.

    • Area: 18.5% of Indian land.

    • Crops: Wheat, Cotton, Pulses, etc.

  4. Black Soil

    • Also known as Regur or Chernozem (cotton soil).

    • Well-known for moisture retention due to volcanic rock composition.

    • Rich in calcium, but poor in nitrogen.

    • Area: Maharashtra, Madhya Pradesh, Gujarat.

    • Crops: Cotton, Oilseeds, etc.

  5. Desert Soil

    • Covers 4.42% of total area; typically found in arid regions.

    • Salinity caused by excessive irrigation.

    • Crops: Bajra, Guar, Fodder, etc.

  6. Mountain Soil

    • Found in hilly and valley areas of the Himalayas.

    • Crops: Maize, Rice, Legumes, etc.

    • Acidic character with low humus.

  7. Peaty and Marshy Soil

    • High organic matter content found in areas of heavy rainfall.

    • Found in delta regions like Sundarbans.

  8. Saline Soil

    • Poor in nutrients, high salinity affects plant growth.

    • Common in coastal regions and arid areas.

Soil Conservation Techniques

  • Shelter Belts: Rows of trees planted to reduce wind movement, preventing soil erosion.

  • Intercropping: Different crops grown in alternating rows to protect soil and enhance fertility.

  • Contour Barriers: Barriers made with stones or grass to slow down water flow and reduce gully formation.

Soil Composition and Properties

  • Common minerals in soil: Iron, Potassium, Magnesium, Calcium, Sulphur.

  • Edaphic factors affecting biodiversity include:

    • Soil structure

    • Temperature

    • pH levels

  • Soil texture impacts drainage, nutrient retention, and suitability for various crops.

    • Sandy Soil: Poor in nutrients, good for carrots and potatoes.

    • Clayey Soil: High in clay particles, used for pots and crafts.

    • Loamy Soil: Balanced mixture, good for general gardening.