National Agricultural Literacy Curriculum Matrix
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Plant-Soil Interactions (Grades 3-5)
3 - 5
Three 45-minute class periods plus observation time
Students learn how plants and soils interact by observing root growth, considering the function of a plant’s roots, modeling the movement of water into the roots, and investigating movement of water and nutrients throughout the plant using pieces of celery stalks and food coloring.
- 1 clear plastic cup or glass per student
- 1 paper towel per student
- 2-3 pea seeds per student
- 3-4 permanent markers for class to use
Each group of 4 students needs:
- 1 drinking glass
- 1 hand lens
- 6 pea or pinto bean (or other type) seeds
- 1 cup of water
- 1 paper towle
For the demonstration:
- 1 paper or styrofoam cup
- 1 large container
- 1 bottle of food coloring
- 1 sharp pencil
- Sharp knife (for the teacher)
Each group of 4 students needs:
- 1 paper styrofoam cup
- 1 piece of celery stalk (approximately 2 inches)
- 1 bottle of food coloring
Essential Files (maps, charts, pictures, or documents)
crop: food crops, lawns, garden, and ornamental plants such as flowers
permeability: the ability of soil to allow the passage of water
Background Agricultural Connections
Interest Approach – Engagement
- Ask the students the following questions to introduce the lesson:
- How do plants take in water and nutrients from the soil?
- How does water and nutrients get from the roots to the rest of the plant?
- Can a plant circulate water and nutrients through the roots, stem, and leaves just like a human's circulatory system circulates blood and nutrients?
Activity 1: How Does a Plant Grow?
- Inform students that they will be looking at the growth of pea seeds over the next few days and that their task for the day is to begin this investigation. Explain that they will be letting pea seeds germinate in a way that they will be able to see the growth of the plants. Demonstrate how the students will set up their pea seeds in a cup with a paper towel and water.
- See preparation for details about setting this up. This step will need to be done several days before students do Activity 2. Make sure students write their names near the top of the cup using a permanent marker.
- For the next few days, allow a few minutes for students to observe their pea seeds.
- Although students cannot handle the roots of their pea plants growing in the cups with water, this method will enable them to visualize the early growth of the root, stem, and then leaves from the pea seed. (If students try to remove the young pea plants from the cup/paper towel setup, the plants will be damaged and they won’t be able to see further growth of the plant.
- After students begin to observe changes or growth in their seeds, ask students to share their observations. Record observations on the board or chart paper. Continue to add to this list for a few days.
- Students can make a variety of observations over time. They may notice that the seed seems to swell or get larger after being in the cup. Then they may observe something sprouting from the seed. The first thing they see will be the root, which grows downward. After a few days, they will see branching of the root system. The stem grows from the seed next. Unlike the root, students will see green color and observe that the stem grows upward. Students will also see small leaves as the stem continues to grow.
Activity 2: From Soil to Roots
- Remind students that in the previous lesson they learned that air spaces in soil become filled with water. Ask, “Why do the plants need water in the soil?” Follow this with the question, “Are there any other things in the water that the plant can take in too?”
- Students’ responses will vary. It is likely that students will suggest that plants need the water to grow. If necessary, guide the discussion to mention the plant’s root system. The second question may be more challenging for students.
- Introduce the word “nutrients” to students. Nutrients are substances that plants and animals need to be healthy.
- Nutrients are not things that can be seen, but are important for health. Students may be familiar with nutrients such as vitamins and minerals in the food they eat or drink. Students cannot see the nutrients in their food or drink but are likely to acknowledge that these substances are important for keeping them healthy. Plants need nutrients as well. The nutrients that plants need are released from soil particles into soil water. Plants need many of the same nutrients that animals do, but some of the needs of plants are different than the needs of animals. Also, the amount of different nutrients that plants need is different than the amounts that animals need.
- Continue the discussion by asking students how plants get their nutrients. What parts of the plant are important for getting nutrients from the soil?
- This discussion is intended to help students begin thinking about how nutrients in soil actually get into plants. At this point, don’t go into detail, but simply acknowledge that roots are important. The remainder of this lesson will help students learn more about how this happens.
- Explain that students will examine the roots of a plant. Divide the students into groups of four. Pass out to each group a young seedling (taken from the paper towel germination) and a hand lens. Tell students that they should look at the roots of the seedling first using just their eyes and then using the hand lens. Ask students to draw a picture of the roots of their seedling.
- When students look at the roots with just their eyes, they may see just a basic root structure. When they use the hand lens, they are likely to notice small, fine projections coming off the roots. These are the root hairs. The root hairs are white and very fine. It may be easier to see the root hairs if students put a dark background behind the roots.
- The use of the hand lens is a way for students to observe things that they cannot see with their eyes alone. If students have difficulty observing root hairs on the roots, don’t spend a great deal of time on this. They will notice other important things about roots, including the fairly large number of branches to the roots.
- After the students have drawn pictures to represent their observations, ask for volunteers to describe what they saw. Students can also compare their observations of these seedlings with the ones they are growing in water in their cups (if they did Activity 1).
- Students will report seeing one large root emerging from the seed. They also will describe fine white hairs growing out from the root. If time permits, post the students’ drawings around the room and allow time for students to look at the drawings of other students.
- Ask students, “Why do you think that plants have so many root branches and root hairs?”
- Student responses will vary. Guide the discussion to bring out that more root hairs mean more area with which to contact water and nutrients in the soil.
- Ask students, “How do nutrients in the soil water get into the root hairs?”
- Students’ responses will vary. At this time, accept all answers.
- Explain that students will now watch a demonstration to investigate the process by which water enters the roots. As you do the steps listed below, have students gather around so they can see what you are doing and what is happening in the investigation.
- Step 1: Fill the cup about half full of water.
- Step 2: Place the cup of water into the center of the larger container.
- Step 3: Fill the larger container with water until its level is the same as that in the cup.
- Step 4: Add several drops of food coloring to the water in the larger container and gently mix the water until the color is evenly distributed through the water. Do not add food coloring to the water in the cup!
- Step 5: Using a sharp pencil, poke two small holes in the cup opposite each other.
- Step 6: Watch the water in the cup for up to five minutes.
- As you lead the demonstration, explain that:
- The cup represents the root,
- the water inside the cup represents water inside the root,
- the water in the larger container represents the water in the soil, and
- the food coloring represents the nutrients dissolved in the water.
- After students have watched the demonstration, reconvene the class. Ask students to state their observations from the demonstration.
- Students will report that the colored water slowly entered the cup.
- Ask students to suggest ideas about how what they saw in the demonstration may be like what happens in the roots of plants.
- The demonstration is a model of how water and nutrients move from outside of the root to the inside of the root.
- Conclude the activity by asking students the following questions. Ask students to indicate by a show of hands whether they agree or disagree with each statement. Ask for volunteers to explain why they think the statements are correct or incorrect.
Activity 3: From Roots to the Plant
- Explain that getting nutrients into the plant roots is an important first step. Ask students, “Do other parts of the plant need water and nutrients?” followed by “How do the water and nutrients get from the roots to the rest of the plant?”
- Students are likely to think that the rest of the plants need water and nutrients but may not have any firm ideas about how that might happen.
- Explain that students are going to investigate how water moves from the roots to the rest of the plant. Ask students to again work in their groups of four.
- Pass out to each student one copy of Master 3.1, Getting Water and Nutrients to the Plant. Read through the instructions for the investigation with the students to ensure that they understand their task.
- Allow time for students to ask questions about the procedure they will follow. After reviewing the instructions, and before having students begin the hands-on part of the experiment, ask students to write their predictions about what will happen with the food coloring, water, and celery.
- As teams work on their investigation, circulate among teams to answer questions and help them with timing the investigation.
- Reconvene the class and ask for volunteers to report their predictions and results about the movement of the food coloring in the celery. Ask them if their predictions were correct or incorrect. Ask them what conclusions they can make about the movement of water and nutrients in plants.
- Students’ predictions will vary. They should report that the food coloring was transported up the celery stalk and was visible as a series of colored dots along the top of the stalk.
- Conclude the lesson by asking students if they can think of a part of their own bodies that moves nutrients or other substances from one place to another. Can they think of ways that the movement of water and nutrients from the roots to other parts of plants is either similar to or different from what they know about the function of blood in the human body?
- Depending on what students have learned about their bodies, they may see some similarities between the movement of water and nutrients in plants and the blood in their own bodies. Students are likely to have some knowledge of blood taking oxygen from the air to their lungs and then other parts of their bodies and also taking carbon dioxide (waste products) away from their cells. Students may also recognize that plants, unlike humans and other animals, do not have pumps (hearts) that pump the blood from one part of the body to another.
- If students do not have this background knowledge, you may choose to omit this step. However, if students have some understanding of the circulatory system, this may help them recognize that living systems of various kinds need to have a way to get nutrients and water to all parts of their bodies.
Concept Elaboration and Evaluation
After conducting these activities, review and summarize the following key concepts:
- Water and nutrients are located in the soil.
- Plants absorb water and nutrients from the soil to their roots. This process removes nutrients from the soil.
- Water and nutrients are then circulated through the plant's vascular system.
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!
Suggested Companion Resources
- Is There Ever Too Much of a Good Thing? (Activity)
- What Do Plants Need to Grow? (Activity)
- How Things Grow (Book)
- 4R Reader (Booklets & Readers)
- SOIL Reader (Booklets & Readers)
- Bottle Biology (Teacher Reference)
- Learn How To Compost (Website)
- Soil Center (Website)
- Soil Science Society of America (Website)
Agricultural Literacy Outcomes
Plants and Animals for Food, Fiber & Energy
- Explain how the availability of soil nutrients affects plant growth and development (T2.3-5.c)
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)
Education Content Standards
4-LS1: From Molecules to Organisms: Structures and Processes
4-LS1-1Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.
5-LS1: From Molecules to Organisms: Structures and Processes
5-LS1-1Support an argument that plants get the materials they need for growth chiefly from air and water.
Common Core Connections
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.
CCSS.ELA-LITERACY.CCRA.SL.2Integrate and evaluate information presented in diverse media and formats, including visually, quantitatively, and orally.
CCSS.ELA-LITERACY.CCRA.SL.3Evaluate a speaker’s point of view, reasoning, and use of evidence and rhetoric.
CCSS.ELA-LITERACY.CCRA.SL.4Present information, findings, and supporting evidence such that listeners can follow the line of reasoning and the organization, development, and style are appropriate to task, purpose, and audience.
CCSS.ELA-LITERACY.CCRA.SL.6Adapt speech to a variety of contexts and communicative tasks, demonstrating command of formal English when indicated or appropriate.
Language: Anchor Standards
CCSS.ELA-LITERACY.CCRA.L.1Demonstrate command of the conventions of standard English grammar and usage when writing or speaking.
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.
CCSS.ELA-LITERACY.CCRA.L.5Demonstrate understanding of figurative language, word relationships, and nuances in word meanings.