Target Grade Level:

K-2

Estimated Time:

Activity 1: 40 Minutes

Activity 2: 60 minutes

Activity 3: 20 Minutes

Activity 4: 40 Minutes

Materials:

Activity 1

Activity 2

Activity 3

  • Apple
  • Paring Knife
  • Cutting Board or plate

Activity 4

Vocabulary:

  • Erosion: process of the gradual destruction or diminution of something; eroding or being eroded by wind, water, or other natural agents.
  • Conservation: protecting and conserving natural resources such as soil and water.
  • Cover Crops: A crop grown for the protection and enrichment of the soil.

Background – Agricultural Connections

Nearly all food can be tracked back to soil. Fruits, vegetables and grains are grown in the soil. Meat, eggs, and dairy products come from animals that eat plants that grow in soil.   

The Midwest is often referred to as the “breadbasket” of the United States. This is because the Midwest has some of the best soil in the world, which is ideal for growing wheat, corn and other grains. Because of this, it is important that we protect our topsoil from wind and water erosion. 

Land that is tilled and left bare is more susceptible to erosion by wind or water. Topsoil that is washed or blown away can take decades to naturally replace. Excess nutrients applied to the soil can reach waterways through runoff and groundwater.

It used to be common for farmers in Iowa to plow the soil in the fall or spring. Plowing completely turns the soil over, leaving it exposed to wind and water. Topsoil, especially on hills, would blow or wash away. When Iowa land was first plowed, the settlers found 14 to 16 inches of topsoil. By 2000, the average was six to eight inches.

In the 1960s, farmers began using chisel plows to prepare the soil for planting. The chisel would make deep slits into the soil. This tillage method did not disrupt the soil as much as plowing, and enabled farmers to grow crops on hills without losing as much soil to wind and water erosion. Minimally tilling the soil is called conservation tillage. It is still used today when tilling is necessary.

Today, many farmers do not till the soil before planting. No-till farming is when farmers plant seeds directly into unbroken soil. Stems, leaves and roots from last year are left on the ground. This helps protect the soil from wind and water erosion. Earthworms and living soil organisms break down last year’s crop residue, providing for air and water movement through the soil and providing organic matter for a good environment for the seeds to germinate and crops to grow.

Farmers use many other conservation practices to keep the topsoil in place and keep nutrients from entering water sources. Cover crops planted on crop fields in the fall help protect our water from becoming polluted with sediment and nitrates. Terraces are used on hilly land to slow water down as it runs off the hill. Buffer strips and bioreactors are used to help filter sediment and nutrients out before it enters streams, ponds, and lakes.

Interest Approach – Engagement

Tell students that Iowa usually ranks first or second in producing four agriculture products. Then ask, “Do you know what they are?” If they are stumped, tell the class that two are crops (plants) and two are products from livestock (animals).  For at least the last 15 years, farmers in Iowa have produced more corn, pork, and eggs than farmers in any other state. Iowa usually ranks number one in soybean production too, but sometimes it is second behind Illinois. 

Then ask, “Why do you think Iowa is such a good state for growing crops and raising livestock?” Iowa is a top agriculture state because of our climate and soil.

Procedures

Activity 1: Natural Resources & Pizza (40 minutes)

  1. As a class, watch the video explaining what natural resources are. 
  2. Ask students if they can name natural resources in the room around them. Write student answers on the board. 
  3. Give each student a copy of the What is it Made of? worksheet. Give students 5 minutes to match the items with the resource they are made from on their own and then review it as a class. After 5 minutes, discuss what each item is made of and the steps it takes to get to the finished product.
    1. Trees are cut down and become wood. Wood is used to make tables and chairs.
    2. Sheep are sheard for their wool. The wool is used to make sweaters.
    3. People drill into the ground to collect oil. The oil is used to make plastic. Plastic is used to make toys.
    4. Sand is heated at high temperatures to create glass. The glass is formed into jars. 
  4. Explain to students that natural resources can be used to make more than physical objects. We can also use natural resources for ingredients in our food and to grow ingredients. Natural resources like coal and gas can also be used to cook and heat up our food before we eat it. 

 

Activity 2: What is Soil? (60 minutes)

  1. Nearly all food can be tracked back to soil. Fruits, vegetables, and grains are grown in the soil. Meat, eggs, and dairy products come from animals that eat plants that grow in soil. 
  2. Ask students to come up with ideas of what soil is and what it is made of. Take 3-4 ideas from students. 
  3. As a class, go through the What is Soil document to learn about soil and its makeup. 
  4. Explain to students that soil can have a different makeup of all the ingredients depending on where it is. The structure of the soil helps determine what can and can’t grow, or the soil’s function. An even mix of all the soil structures leads to healthy soil that can hold water for the plant to access. Iowa has very healthy soil which is part of why we have so much crop land. 
  5. Help students make connections to soil structure using the water permeability experiment
    1. Set up 3 clear cups with coffee filters and funnels. Place the coffee filter inside the funnel so it drains into the cup. In the 1st cup fill the funnel with sand. In the 2nd cup fill the funnel with a topsoil mix. In the 3rd cup fill the funnel with clay. 
  6. Have students make predictions on which soil structure will allow the most water flow. Which soil structure will allow the least water flow?
  7. Pour an equal amount of water into each cup over the substrate in the funnel. 
  8. Have students observe the water flow through each of the cups.
  9. Discuss with students the results. Ask them which one would be best for plants, and why.

 

Activity 3: Apple Earth (20 minutes)

  1. Ask the students, “How much of the world has topsoil that is suitable for growing crops?” (Hold up the apple) This apple represents planet Earth. We’re going to cut the apple into pieces to see how much of the Earth can be used to grow food for more than 8 billion people and all the animals in our care.
  2. Let’s start by thinking about water. How much of the world is water? Cut the apple lengthwise in four equal parts and take away three. These three parts represent the water on Earth.  3/4 or 75% of the Earth is made up of water. Ask students where we find water on planet Earth. (Oceans, rivers, revisions)
  3. Ask students what places are too hot?  (Deserts and places near the equator.) What places are too cold? (The poles, places where there is frozen ground). How much of the land is too hot or too cold to grow crops? Cut the remaining quarter in half lengthwise and take away half. This half represents the areas on Earth that are too hot, too cold, or too wet for the plants we eat to grow. 1/8 of the Earth has land in a climate that is unable to grow or produce food.
  4. What places other than bodies of water are too wet? (Swamps and the rainforest.) Can we grow food on all the remaining land? (Cut the remaining portion into four equal parts and take away three.) These three parts represent areas of Earth where the plants we eat can’t grow roots in the ground. We call these surfaces impervious, which means incapable of penetrating or being passed through. Ask students what things cover soil and make the ground impenetrable? (Roads, houses, businesses, shopping malls, schools, parking lots, mountains, forests.)
  5. The fourth portion – only 1/32 of Earth – represents the land that can grow crops for the 7+ billion people and animals on Earth.
  6. Can we grow food to the core of the Earth? No. (Peel the skin off the remaining section.) This skin represents topsoil, the part of the soil that plants grow in. This is the amount of soil on planet Earth that grows the food to feed all the people and animals that live around the world.
  7. Ask students if this is very much topsoil on planet earth to grow our food? (No.) Ask students if the amount of land with good topsoil on the Earth is getting bigger or smaller?  It is getting smaller because land is being used for housing, businesses, schools, and other things that our growing population needs. The amount of topsoil on the land is also decreasing because of wind and water erosion.

 

Activity 4: Conservation Practices (40 minutes)

  1. The last two activities taught us that good topsoil is needed to grow crops and only a small portion of the earth has topsoil that is well suited for growing food for us and livestock. Now we are going to learn what farmers can do to protect this valuable and limited resource—topsoil.
  2. Ask students for examples of how their families conserve natural resources. (Examples include recycling paper, turning off the water when brushing their teeth)
  3. Explain that over time, people have learned that conserving natural resources is important and they have changed how we do things to conserve and protect the environment. Science and technology have helped us conserve natural resources, too.  Discuss a few examples of environmentally friendly technologies (Examples: include improved methods to recycle materials, water and energy-saving appliances, fuel efficient cars, programable thermostats, etc.) 
  4. Explain to students that cover crops are one way that farmers help to conserve their soil. 
  5. As a class watch the What are Cover Crops video to learn about what cover crops are and how farmers use them to protect soil. 
  6. The class can now practice planting their own cover crops by making cover crop monsters. Learn how to make them by watching the Cover Crop Monsters video

 

Extension Activities 

Suggested Companion Resources 

N/A

Sources/Credits

Author(s) 

Alyson McCarty

Organization Affiliation 

Iowa Agriculture Literacy Foundation

Extension Activities 

Organization Affiliation 

Iowa Agriculture Literacy Foundation

Agriculture Literacy Outcomes

  • T1.K-2. Describe the importance of soil and water in raising crops and livestock.

 

Iowa Core Standards

  • Literacy
    1. RI.K.1. With prompting and support, ask and answer questions about key details in a text.
    2. RI.K.2. With prompting and support, identify the main topic and retell key details of a text.
    3. SL.K.1. Participate in collaborative conversations with diverse partners about kindergarten topics and texts with peers and adults in small and larger groups.
      • Follow agreed-upon rules for discussions (e.g., listening to others and taking turns speaking about the topics and texts under discussion).
      • Continue a conversation through multiple exchanges.
    4. SL.K.5. Add drawings or other visual displays to descriptions as desired to provide additional detail.
    5. RI.1.1. Ask and answer questions about key details in a text.
    6. RI.1.2. Identify the main topic and retell key details of a text.
    7. SL.1.1. Participate in collaborative conversations with diverse partners about grade 1 topics and texts with peers and adults in small and larger groups.
      • Follow agreed-upon rules for discussions (e.g., listening to others with care, speaking one at a time about the topics and texts under discussion).
      • Build on others’ talk in conversations by responding to the comments of others through multiple exchanges.
      • Ask questions to clear up any confusion about the topics and texts under discussion. 
    8. RI.2.1. Ask and answer such questions as who, what, where, when, why, and how to demonstrate understanding of key details in a text.
    9. SL.2.1. Participate in collaborative conversations with diverse partners about grade 2 topics and texts with peers and adults in small and larger groups.
      • Follow agreed-upon rules for discussions (e.g., gaining the floor in respectful ways, listening to others with care, speaking one at a time about the topics and texts under discussion).
      • Build on others’ talk in conversations by linking their comments to the remarks of others.
      • Ask for clarification and further explanation as needed about the topics and texts under discussion.
  • Social Studies
    1. SS.K.1. Recognize a compelling question.
    2. SS.K.3. Construct responses to compelling questions using examples.
    3. SS.1.4. Construct responses to compelling questions using examples.
    4. SS.2.4. Construct responses to compelling questions using reasoning, examples, and relevant details.