🌱 Soil

 

🔹 What is Soil?

Soil is the top layer of the Earth’s surface where plants grow. It is made of:

• Mineral particles (sand, silt, clay)
• Organic matter (dead plants and animals)
• Air and water
• Living organisms (worms, bacteria, fungi)

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🔹 Soil Formation

Soil forms very slowly through a process called weathering:

• Physical weathering – rocks break into smaller pieces
• Chemical weathering – rocks change due to chemicals
• Biological weathering – plants and animals help break rocks

👉 It can take hundreds to thousands of years to form just a thin layer of soil.

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🔹 Soil Profile (Layers of Soil)

Soil is arranged in layers called a soil profile:

1. Topsoil (A horizon)
   • Rich in nutrients and organic matter
   • Best for plant growth
2. Subsoil (B horizon)
   • Contains minerals washed down from topsoil
3. Parent rock (C horizon)
   • Weathered rock fragments

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🔹 Types of Soil

• Sandy soil – drains water quickly, low nutrients
• Clay soil – holds water, can become waterlogged
• Loam soil – mixture of sand, silt, and clay (best for farming)

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🔹 Importance of Soil

Soil is very important because it:

• Supports plant growth (food production 🌾)
• Stores water
• Recycles nutrients
• Provides habitat for organisms
• Helps control climate by storing carbon

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🔹 Soil Erosion

Soil erosion is the removal of topsoil by:

• Wind
• Water (rain, rivers)
• Human activities (deforestation, overgrazing)

👉 This is dangerous because topsoil is the most fertile layer.

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🔹 Soil Degradation

Soil degradation means soil quality becomes worse due to:

• Overuse of land
• Pollution (chemicals, pesticides)
• Salinization (salt build-up)
• Desertification (land becomes desert-like)

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🔹 Soil Conservation Methods

To protect soil, we can:

• Plant trees (afforestation)
• Use contour ploughing (plough along slopes)
• Practice crop rotation
• Avoid overgrazing
• Build terraces on hills
• Use organic fertilizers 

Mr. Amir Salih—Social Studies—Environmental