Agricultural Literacy Curriculum Matrix
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What's in Soil?
3 - 5
Students will identify the components of soil and demonstrate that soil contains air and water.
- 2-cup soil samples, 1 per pair of students
- Hand lenses
- Tissue paper or thin paper towel (the thick, brown paper towels common in schools do not work)
- Overhead projector
- 1-cup measuring cups, 1 per pair of students
- 2-cup containers, 1 per pair of students (preferably clear, e.g. plastic cups, mason jars)
- Soil Pie: Components of the Soil handout, for display
- Piece of yarn
Essential Files (maps, charts, pictures, or documents)
infiltration: the movement of water into the soil surface
mineral matter: small pieces of weathered rock (parent material) that has been broken down into small particles over thousands of years
organic matter: a soil component derived from once-living organisms like plants and animals
percolation: the movement of water within and through the soil
pores: the spaces between soil particles and between soil aggregates; pores can be filled with air or water
soil structure: the arrangement of soil particles into aggregates, which contain solids and pore space
saturation: occurs in a soil when all of the pores are filled with water, leaving no air
Did you know? (Ag Facts)
- Soil contains all three states of matter; solids (minerals and organic matter), liquids (water), and gases (carbon dioxide, oxygen).1
- Soil is one of the most important natural resources known to man.3
- Soil scientists study the upper few meters of the Earth’s crust.1
- A single shovelful of soil can contain more living things (organisms) than live in the Amazon rain forest.2
- Just a teaspoonful of forest soil can hold more than 10 miles of fungi (mushrooms, mold, yeasts, and mildews).2
Background Agricultural Connections
Interest Approach – Engagement
- Begin a discussion with students and ask, Why is soil important? Accept all answers and record them on chart paper or somewhere in the classroom where the responses are visible. Next, display the Illinois Ag in the Classroom Ag Mag, titled Soil on the whiteboard. Paper copies can be printed if a whiteboard is not available. Have a student read the section on the first page that addresses the importance of soil. Compare the students' responses to those found in the reading. Ask another student to read aloud the section on page 2 that addresses soil parts and add more information to the list as to why soil is important.
- Review all responses and ask, How much soil exists on earth that farmers can access to grow crops or raise livestock? Accept all answers and add these responses to the chart paper. To respond to this question, refer the students to the section of the Ag Mag, titled A Slice of Soil found on page 3. You will need an apple and a paring knife to demonstrate the activity and answer the question as to how much farmable soil is available to farmers.
- Challenge students to think of ways farmers can conserve soil to produce enough food to feed the world. If time permits, play one of the videos on the last page of the Ag Mag that interviews two individuals who work in the field of soil science to help students understand the importance of soil and ways farmers practice conservation. The videos can be shown from an interactive whiteboard. Look for the blue video cameras to play each video.
Activity 1: Soil Inventory
- Divide students into pairs. Give each pair a soil sample. Ask students to pour their sample out onto a newspaper.
- Note: Students may bring samples from home, but instruct them to collect true soil, not a soilless media. Many potting mixtures are made mostly of organic matter and contain little or no mineral matter. Ensure that samples are collected from a variety of locations.
- Using a hand lens, ask each pair of students to observe their sample and write a description, noting everything that they see or feel. Mineral matter will look like small, bead-like, particles, or little rock-like pieces. Leaves, sticks, roots, and living creatures like worms and beetles comprise the organic matter component. Water content can be felt as moisture. Students probably will not identify air as a component in their soil because they cannot see it.
- Show students the Soil Pie: Components of the Soil handout. Tell them that the four components of soil are mineral matter, organic matter, air, and water. Everything they observed in their soil sample should fit into one of these categories.
Activity 2: Soil Moisture
- Pick one of the soil samples that feels moist or appears to have the most organic matter.
- Place the tissue paper or paper towel on an overhead projector. Notice that it blocks out the light. Place a drop of water on the paper towel to illustrate that some of the light now shines through.
- Place the moist soil sample on the paper towel, and after a few minutes, depending on how wet your sample is, pour the soil off. Replace the paper towel on the projector to see if the soil left any more moisture in the towel. This will illustrate that soils do hold moisture.
- Repeat with different soil samples to show that the moisture content of soils varies.
Activity 3: Soil Air
- Ask each student pair to measure out 1 cup of dry soil from their samples and place it into a 2-cup container. A clear container will allow students to watch how the water infiltrates and then percolates through the soil.
- Next, students should fill their measuring cups with 1 cup of water and slowly pour it into the soil container until the soil is saturated. Stop pouring as soon as the sample is saturated, no more air bubbles emerge, and water has just begun to pool on the surface of the soil without infiltrating.
- Students should measure the amount of water left and subtract it from 1 cup.
- Lead students to infer that the amount of water added to the soil sample represents approximately the amount of air that was displaced.
- Have students compare the amounts of water that they were able to pour into their soil samples. There will be differences depending on the soil texture and organic matter content. Calculate the percentage of air in the soil samples. For example, if 1/4 cup of water was needed to saturate the soil, the sample contained 25% air.
- Tape one end of the yarn to the center of the “Soil Pie: Components of the Soil” handout. Take the loose end and move it up and down between the water and air components to show how they displace each other. Discuss climatic conditions that would lead soils to contain more air or water.
- Discuss what you have learned:
- What are the components of soil? (mineral matter, organic matter, water, air)
- Which two components are the most variable? (water and air) Why?
- What does it mean when a soil is saturated?
- What would happen to a farm field if it was saturated for a very long time? (pore spaces completely filled with water; crops may die or be very stunted)
Concept Elaboration and Evaluation:
After conducting these activities, review and summarize the following key concepts:
- Soil is a natural resource that farmers use to provide our food.
- Soil is necessary to grow the plants which provide food for humans and animals. Soil is also used to grow plants which provide clothing (cotton) and fuel.
- Soil contains mineral matter and organic matter. It also contains water and air.
We welcome your feedback! Please take a minute to tell us how to make this lesson better or to give us a few gold stars!
For an activity illustrating soil particle sizes, see the lesson Soil Texture and Water Percolation.
Suggested Companion Resources
- Dirt: The Scoop on Soil (Book)
- Jump Into Science: Dirt (Book)
- Life in a Bucket of Soil (Book)
- Mountains of Jokes About Rocks, Minerals, and Soil (Book)
- Rocks and Soil (Book)
- Sand and Soil: Earth's Building Blocks (Book)
- Seed, Soil, Sun: Earth's Recipe for Food (Book)
- Soil! Get the Inside Scoop (Book)
- You Wouldn't Want to Live Without Dirt! (Book)
- Topsoil Tour (Kit)
- Dirt: Secrets in the Soil (DVD) (Multimedia)
- Your Day With NPK Online Game (Multimedia)
- SOIL Reader (Booklets & Readers)
- From the Ground Up: The Science of Soil (Website)
- Rocks and Soils (UEN Sci-ber Text for 4th Grade) (Website)
- Soil Center (Website)
- Soil Science Society of America (Website)
State Standards for Utah
Grade 4: Science Standard 3Students will understand the basic properties of rocks, the processes involved in the formation of soils, and the needs of plants provided by soil.
Objective 3Observe the basic components of soil and relate the components to plant growth. Meeting one or more of the following indicators: a) Observe and list the components of soil (i.e., minerals, rocks, air, water, living and dead organisms) and distinguish between the living, nonliving, and once living components of soil. b) Diagram or model a soil profile showing topsoil, subsoil, and bedrock, and how the layers differ in composition. c) Relate the components of soils to the growth of plants in soil (e.g., mineral nutrients, water). d) Explain how plants may help control the erosion of soil. e) Research and investigate ways to provide mineral nutrients for plants to grow without soil (e.g., grow plants in wet towels, grow plants in wet gravel, grow plants in water).
Agricultural Literacy Outcomes
Agriculture and the Environment
- Explain how the interaction of the sun, soil, water, and weather in plant and animal growth impacts agricultural production (T1.3-5.b)
- Recognize the natural resources used in agricultural practices to produce food, feed, clothing, landscaping plants, and fuel (e.g., soil, water, air, plants, animals, and minerals) (T1.3-5.e)
Common Core Connections
Reading: Anchor Standards
CCSS.ELA-LITERACY.CCRA.R.1Read closely to determine what the text says explicitly and to make logical inferences from it; cite specific textual evidence when writing or speaking to support conclusions drawn from the text.
CCSS.ELA-LITERACY.CCRA.R.7Integrate and evaluate content presented in diverse media and formats, including visually and quantitatively, as well as in words.
Speaking and Listening: Anchor Standards
CCSS.ELA-LITERACY.CCRA.SL.1Prepare for and participate effectively in a range of conversations and collaborations with diverse partners, building on others’ ideas and expressing their own clearly and persuasively.
Language: Anchor Standards
CCSS.ELA-LITERACY.CCRA.L.4Determine or clarify the meaning of unknown and multiple-meaning words and phrases by using context clues, analyzing meaningful word parts, and consulting general and specialized reference materials, as appropriate.
5-ESS2: Earth's Systems
5-ESS2-1Develop a model using an example to describe ways in which the geosphere, biosphere, hydrosphere, and/or atmosphere interact.
5-LS2 Ecosystems: Interactions, Energy, and Dynamics
5-LS2-1Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.