10. Particle Size
The size of the particles in the soil – it affects
how gritty a soil feels when you rub it between your
fingers. It also affects how large the spaces in the soil
will be and how quickly water will pass through.
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13. • Usually in the form of QUARTZ .
• Large in particles (0.063 mm to 2.0 mm) .
• Dry and gritty in texture .
• Safe bearing capacity
» Coarse sand - 4.5 kg/cm2
» Medium sand - 2.5 kg/cm
2
» Fine sand - 1.5 kg/cm
2
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14. Silty Soil
• Mineral origin is QUARTZ and FELDSPAR .
• It exist as soil deposited at the bottom of river water .
• Particles are smaller than sandy soil (0.002 mm to
0.063 mm) .
• Smooth & Round in shape .
• Has a floury feel when dry, and a slippery feel when
wet .
• Safe bearing capacity - 1.5 kg/cm2
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15. Clay
• It formed by over long time chemical weathering of rocks.
• Particles are smaller than 2 μm.
• Has a good water storage quality.
• Sticky when wet, smooth when dry.
• Clay is one of the oldest building materials on Earth.
• Clay baked into brick.
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16. Peaty Soil
• Dark brown or black in color .
• High water content and rich In organic matter .
• Spongy texture .
• Peat is used in water filtration .
17. Saline Soil
• White surface due to salt crystals .
• Bad for plant growth .
• Dry due to high salt content .
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18. Loam Soil
• Ideal soil for growing plants .
• Particle size is less than 63 µm .
• Uniform soil texture .
• High permeability and water holding
capacity .
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20. Forest Floor
This is the top layer of soil that is made up of
living and decomposed materials like leaves,
plants, and bugs. This layer is very thin and is
usually pretty dark.
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21. Topsoil
It is located just below the forest floor. This layer
is made up of minerals and decomposed organic
matter and it is also very dark in color .This is the
layer that many plants roots grow in.
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22. Subsoil
It is located just below the topsoil. This layer
has clay and mineral deposits and less organic
materials than the layers above it. This layer is
also lighter in color than the layers above it.
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23. Parent Rock
It is located just below the subsoil. This layer is
made up of slightly unbroken rock and only a
little bit of organic material is found here. Plant
roots are not found in this layer.
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24. Bedrock
This layer denotes the layer of partially
weathered bedrock at the base of the soil
profile. Unlike the above layers, bed rocks
largely comprise continuous masses of hard
rock that cannot be excavated by hand.
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25. Conclusion
Soil has the most important role on growing
living organisms and structures. To make a
proper and sound structure and environment we
must know the soil.
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We tried to inform about the first step
of knowing soil.