Soil Composition and Ecological Roles

The video explains soil as a vital natural resource, detailing its composition, types, and role in supporting plant growth. It covers the formation of soil through weathering and erosion, the importance of humus, and the different soil types like sand, silt, clay, and loam. The video highlights how soil properties affect plant growth and the role of worms in maintaining soil health. It also explores various uses of soil, including in construction, pottery, and medicine.

What is the primary role of soil in the ecosystem?

• To serve as a foundation for buildings

• To provide a habitat for fish

• To generate electricity

• To supply nutrients to plants

Which process breaks down rocks into smaller pieces to form soil?

• Erosion

• Weathering

• Sedimentation

• Compaction

What is humus primarily composed of?

• Decayed plants and animals

• Water

• Sand particles

• Minerals

Which layer of soil is rich in humus and supports plant growth?

• Subsoil

• Topsoil

• Bedrock

• Clay layer

Which type of soil has the largest particles and drains water quickly?

• Loam

• Sand

• Silt

• Clay

Why is loam considered the best soil for growing plants?

• It has no organic matter

• It is made entirely of sand

• It contains a perfect balance of air, water, and nutrients

• It is composed only of clay

How do roots help in preventing soil erosion?

• By absorbing all the water

• By holding the soil together

• By blocking sunlight

• By attracting earthworms

What farming practice helps maintain nutrient-rich topsoil?

• Planting the same crop repeatedly

• Using only clay soil

• Crop rotation

• Overwatering

What is a significant ecological role of earthworms in soil?

• They eat plant roots

• They create tunnels that aerate the soil

• They dry out the soil

• They block water flow

How is soil used in traditional building practices?

• As a substitute for wood

• As a primary material for glass

• To create mud bricks for construction

• To replace metal structures