Soil is like humus

What is in soil?

What is in soil?

Weathered rock, organic matter, air, and water

What is weathered rock?

Rocks that are broken down by wind, water, & ice.

What is organic matter?

Decayed plants and animals

What are the four types of soil?

Sand, silt, clay, and loam

What is loam?

Combination of sand, silt, and clay

Which type of soil supports plants best?

Loam

Which type of soil holds the most water? Why is it important? What problems can it cause?

Clay - It holds onto water and nutrients for the plant. It can cause plants to become waterlogged and rot.

Put the soil particles in order from the largest to the smallest.

Sand, silt, clay

What is another name for layers of the soil?

Horizons

What is humus?

Organic matter full of nutrients

Which soil layer contains loose soil that is rich in organic material needed by plants?

Topsoil

Which soil layer is made up of unweathered solid rock beneath all the other layers?

Bedrock

What is the texture of sand?

Dry, gritty, or grainy

What is the texture of silt?

Smooth, powdery or slippery

What is the texture of clay?

Sticky when wet; clumps when dry

What is the texture of humus?

Moist, crumbly

What type of soil retains (holds) little water? Why is it important? What problems can it cause?

Sand. It provides drainage for the plant. It cannot hold onto nutrients.

Why is organic matter important for soil?

It improves water holding and helps stick the soil together.

Which layer of soil has less humus and is often filled with clay?

Subsoil

How do earthworms help the soil?

Their droppings add nutrients to the soil. They burrow into the soil & provide water & air pockets.

Why is soil so different worldwide? What types of conditions contribute to the formation of soil or lack of formation of soil?

Because of differences in climate, the type of rocks present, and the rate of weathering. Soils develop faster in warm, moist climates and slowest in cold, arid climates. Rainfall is one of the most important climate factors.

Why is soil so important?

It anchors trees & plants, provides nutrients & minerals, protects from erosion, holds water, source of raw materials, regulates the carbon cycle, food/home for animals. Because without soil there would be no life on earth.

How do scientists classify soil? What are the properties of soil?

They classify them by color, permeability, porosity, and texture.

Name some practical uses of soil.

Farming, foundations for buildings, plant growth including forests, regulate the flow of water, homes for millions of organisms, preserves historical objects, filters water

How long does it take to make 1 inch of soil?

100 to 500 years

What does soil offer plants that they need?

minerals

What are the 5 factors that influence soil formation?

Time- soil properties may vary depending on how long the soil has been weathered

Climate- affects the rate of weathering

Parent material-all soil comes from rocks known as the parent material soil minerals come from this through weathering

Landforms-affect the drainage, erosion, and deposition of soil

Organisms- (plants, animals, micro-organisms, humans)influence soil formation