Soil: Can you dig it?

Soil Formation and Earth’s Structure

Mr. Mendoza

Soil Formation

What is the first step in soil formation?

The weathering of rocks

Mosses and lichens are called pioneer organisms because they are the first organisms to grow on rocks

What is the second step in soil formation?

the addition of humus (decaying organic matter)

Multiple Choice

One component of soil is decayed plant and animal remains, but the major component of soil is - 

• Fossil Fuels
• Weathered rocks
• Iron ore
• Salt water

Multiple Choice

Plants and animals become part of soil when they -- 

• Die and Decay
• Produce offspring
• Grow and Develop
• Take in nutrients

Multiple Choice

Soil is composed of all of these natural materials EXCEPT

• weathered rock
• plant matter
• plastic substances
• animal remains

Soil Profile- Draw this!(SS)

A soil profile is a cross section of soil.

There are three major soil horizons – A, B, and C.

Horizon A

top & darkest layer (high concentration of organic matter - humus)

Top soil

Horizon B

subsoil enriched with clay minerals leached from the topsoil.

Horizon C

bottom layer (weathered rock)

Parent Rock

Multiple Choice

What is the name of Horizon 1?

• Subsoil 
• Topsoil
• Bedrock 
• Parent Rock

Multiple Choice

What is the name of Horizon 2?

• Subsoil 
• Topsoil
• Bedrock 
• Parent Rock

Multiple Choice

What is the name of Horizon 3?

• Subsoil 
• Topsoil
• Bedrock 
• Parent Rock

Factors Affecting Soil Profiles

Topography (slope) of the land – Soils on slopes tend to be thinner soils in flat areas like valleys or plains are thicker

Age – older soils are thicker because they have had more time to develop.

Climate

Distribution of Soil Types

Soil Textures

Particles of soil are classified by size.

The particles of soil are clay, silt, & sand.

What determines a soil’s texture?

The relative proportions of these particles.

The texture of a soil affects its capacity to absorb and retain water & support plant growth.

Soil Texture Triangle

Multiple Choice

What are loam, clay loam, silt loam, and clay?

• Soil particle sizes

• Soil Textures

• Soil pH

• Soil composition

Multiple Choice

What does the size of the soil particles determine?

• pH

• mineral composition

• texture

• horizon posiition

Multiple Choice

Which of the following is NOT one of the three layers of soil?

• topsoil
• undersoil
• subsoil
• bedrock

Multiple Choice

Ellen grabs a topsoil sample in her hand. She rolls it into a ball. The soil feels gritty and the ball falls apart. What part of the topsoil most likely made the topsoil feel gritty?

• clay
• sand
• silt
• humus

Multiple Choice

Which of the following is the largest particle in soil?

• sand
• silt
• humus
• clay

Multiple Choice

The texture of soil depends mainly on

• the types of plants that grow in the soil.
• the size of the particles in the soil.
• the color of the soil.
• the number of worms in the soil.

Multiple Choice

You dig a small hole in the soil and the next day it rains. The hole fills with water, but does not empty even after several days of dry weather. What is the soil mostly made of?

• clay
• sand
• humus
• silt

Multiple Choice

Soil is made of

• Weathered rock
• decomposed plants and animals
• air and water
• all of the above

Multiple Choice

What are the three soil particles that we use to classify soils?

• sand, dirt, and soil
• clay, sand, and silt
• silt, loam, and sandy loam
• clay, salt, and pebbles

Multiple Choice

What do we call the different layers of soil?

• Deposits

• Horizons

• Minerals

• Rocks

Multiple Choice

Which soil horizon is on the bottom?

• topsoil

• subsoil

• bedrock

• bottomsoil

Multiple Choice

What horizon is just below the topsoil?

• soil

• subsoil

• topsoil

• terrace farming

Multiple Choice

Which horizon of soil contains leaf litter, and other organic matter?

• O - Humus/Organic

• A - Topsoil

• B - Subsoil

• R - Bedrock

Multiple Choice

The ___________________ the grain size, the faster the water will move through the soil.

• more mixed
• smaller
• larger

Multiple Choice

The rock particles in soil arranged from largest to smallest are

• Sand, clay, and silt.

• Silt, sand, and clay.

• Sand, silt, and clay.

• Clay, sand, and silt.

Multiple Choice

The best soil for growing plants is

• mostly sand.

• mostly silt.

• mostly clay.

• a mixture of sand, silt, and clay.

Multiple Choice

The layer of loose, weathered material on Earth's surface in which plants can grow is

• topsoil

• humus

• weathering

• bedrock

Multiple Choice

A(n) ______ is a substance with a pH less than 7

• Acid
• Alkaline/Base

Multiple Choice

The sand, silt, and clay portion of soil comes from weathered _____ material.

• parent
• bedrock
• plant
• insect

Multiple Choice

Most plants grow best in soils with a pH between _____.

• 1 and 4
• 4 and 10
• 5 and 7
• 6 and 12

Multiple Choice

The elements are organized into what two groups?

• gaseous; liquid

• liquid; solid; gas

• macronutrients; micronutrients

• none of the above

Multiple Choice

What are the 3 nutrients required on fertilizer labels?

• NDA

• NPK

• KPH

• CHN

Multiple Choice

What is a mixture of weathered rock, decayed organic matter, mineral fragments, water, and air called?

• soil
• organic matter
• decomposed matter

Multiple Choice

What is the remains of something that was once alive?

• inorganic matter
• organic matter

Multiple Choice

What is the process of changing once living material into dark colored organisms?

• composition
• decomposition

Multiple Choice

Texture of Soil:
Sand feels...

• rough
• smooth
• sticky

Multiple Choice

Texture of Soil:
Silt feels...

• rough
•  smooth
• sticky

Multiple Choice

Texture of Soil:
Clay feels...

• rough
• smooth
• sticky

Multiple Choice

What is made up of equal parts of clay, sand, and silt is called

• foam
• loam
• soil

Multiple Choice

What is the average weather of an area called?

• temperature
• topography
• climate

Multiple Choice

What is all of the organisms that live in a region that allows air and water into a soil?

• parent material
• biota
• topography

Multiple Choice

What is the shape of the land?

• parent material
• topography
• biota

Multiple Choice

Organisms that break the remains of dead organisms into smaller pieces and digest them with chemicals are called

• decomposers
• composers

Multiple Choice

Equal layers of soil formed from the movements of the products of weathering is called

• horizons
• decomposers
• composers

Multiple Choice

What breaks down and digests plant remains?

• fungi
• bacteria
• earthworms
• burrowing animals

Multiple Choice

What are microscopic decomposers that cause decay?

• fungi
• bacteria
• earthworms
• burrowing animals

Multiple Choice

What does most of the work mixing humus with other material in soil and eats through the soil?

• fungi
• bacteria
• earthworms
• burrowing animals